diff --git a/frontend/src/app/dashboard/glossaries/[id]/page.tsx b/frontend/src/app/dashboard/glossaries/[id]/page.tsx
index a1bbd01..8bfb140 100644
--- a/frontend/src/app/dashboard/glossaries/[id]/page.tsx
+++ b/frontend/src/app/dashboard/glossaries/[id]/page.tsx
@@ -35,6 +35,21 @@ function getDisplayTarget(
   return translations[lang] || term.target;
 }
 
+/** Source term in the given language.
+ * - 'fr' → term.source (the original French)
+ * - 'multi' / '' / undefined → term.source (no language chosen, default to FR)
+ * - other langs → term.translations[lang] (the translated source)
+ *   - falls back to term.source if missing
+ */
+function getDisplaySource(
+  term: { source: string; translations?: Record<string, string> | null },
+  lang: string
+): string {
+  if (!lang || lang === 'multi' || lang === 'fr') return term.source;
+  const translations = term.translations || {};
+  return translations[lang] || term.source;
+}
+
 export default function GlossaryDetailPage() {
   const params = useParams();
   const router = useRouter();
@@ -84,12 +99,18 @@ export default function GlossaryDetailPage() {
     if (name.trim() !== glossary.name) return true;
     if (sourceLanguage !== (glossary.source_language || 'fr')) return true;
     if (targetLanguage !== (glossary.target_language || 'multi')) return true;
-    const currentTerms = terms
-      .filter((t) => t.source.trim() && t.target.trim())
-      .map((t) => `${t.source}|${t.target}`).sort().join(';;');
-    const originalTerms = glossary.terms
-      .map((t) => `${t.source}|${t.target}`).sort().join(';;');
-    return currentTerms !== originalTerms;
+    // Compare normalized term payloads (source + target + translations dict).
+    const normalize = (termList: Array<{ source: string; target: string; translations?: Record<string, string> | null }>) =>
+      termList
+        .filter((t) => t.source.trim() && t.target.trim())
+        .map((t) => {
+          const tr = t.translations || {};
+          const trKeys = Object.keys(tr).sort();
+          return `${t.source}|${t.target}|${trKeys.map((k) => `${k}=${tr[k]}`).join(',')}`;
+        })
+        .sort()
+        .join(';;');
+    return normalize(terms) !== normalize(glossary.terms);
   }, [glossary, name, sourceLanguage, targetLanguage, terms]);
 
   const validTerms = terms.filter((t) => t.source.trim() && t.target.trim());
@@ -114,7 +135,37 @@ export default function GlossaryDetailPage() {
   };
 
   const handleTermChange = (index: number, field: 'source' | 'target', value: string) => {
-    setTerms(terms.map((t, i) => (i === index ? { ...t, [field]: value } : t)));
+    setTerms(terms.map((t, i) => {
+      if (i !== index) return t;
+      const translations = { ...(t.translations || {}) } as Record<string, string>;
+
+      if (field === 'source') {
+        if (!sourceLanguage || sourceLanguage === 'fr') {
+          // French source → write to term.source
+          return { ...t, source: value };
+        }
+        // Other source languages → write to translations[sourceLanguage]
+        translations[sourceLanguage] = value;
+        return { ...t, source: t.source, translations };
+      }
+
+      if (field === 'target') {
+        if (!targetLanguage || targetLanguage === 'multi' || targetLanguage === 'en') {
+          // Default target → write to term.target
+          return { ...t, target: value };
+        }
+        // Other target languages → write to translations[targetLanguage]
+        translations[targetLanguage] = value;
+        return { ...t, target: t.target, translations };
+      }
+
+      return t;
+    }));
+  };
+
+  const handleSourceLanguageChange = (newLang: string) => {
+    setSourceLanguage(newLang);
+    // No term remapping needed — the display reads translations[newLang] on the fly.
   };
 
   const handleTargetLanguageChange = (newLang: string) => {
@@ -363,16 +414,21 @@ export default function GlossaryDetailPage() {
             <label className="text-[10px] font-bold uppercase tracking-widest text-brand-dark/50 dark:text-white/50 mb-1.5 block">
               {t('glossaries.detail.sourceLang') || 'Langue source'}
             </label>
-            <div className="h-10 rounded-lg border border-input bg-muted/40 px-3 flex items-center gap-2 text-sm text-brand-dark/70 dark:text-white/70">
-              <span className="text-base leading-none">🇫🇷</span>
-              <span>Français</span>
-              <span className="ml-auto text-[10px] text-brand-dark/40 dark:text-white/40 uppercase tracking-wider font-medium">
-                {t('glossaries.detail.sourceLocked') || 'fixé'}
-              </span>
-            </div>
+            <select
+              value={sourceLanguage}
+              onChange={(e) => handleSourceLanguageChange(e.target.value)}
+              disabled={isUpdating}
+              className="w-full h-10 rounded-lg border border-input bg-background px-3 text-sm focus:outline-none focus:ring-2 focus:ring-brand-accent/20"
+            >
+              {SUPPORTED_LANGUAGES.filter((l) => l.code !== 'multi').map((l) => (
+                <option key={l.code} value={l.code}>
+                  {l.flag} {l.label}
+                </option>
+              ))}
+            </select>
             <p className="text-[10px] text-brand-dark/40 dark:text-white/40 font-light mt-1.5">
-              {t('glossaries.detail.sourceLockedNote') ||
-                'Les templates ne stockent la source qu\'en français. Le multilingue source est sur la roadmap.'}
+              {t('glossaries.detail.sourceLangNote') ||
+                'La source originale est en français. Pour les autres langues, on lit le champ translations du terme (s\'il existe).'}
             </p>
           </div>
           <div>
@@ -462,7 +518,7 @@ export default function GlossaryDetailPage() {
                   >
                     <td className="px-6 py-1.5">
                       <input
-                        value={term.source}
+                        value={getDisplaySource(term, sourceLanguage)}
                         onChange={(e) => handleTermChange(term._index, 'source', e.target.value)}
                         disabled={isUpdating}
                         placeholder={t('glossaries.detail.sourcePlaceholder') || 'terme source'}
@@ -471,9 +527,7 @@ export default function GlossaryDetailPage() {
                     </td>
                     <td className="px-3 py-1.5">
                       <input
-                        value={targetLanguage === 'multi' || targetLanguage === 'en'
-                          ? term.target
-                          : (term.translations?.[targetLanguage] || term.target)}
+                        value={getDisplayTarget(term, targetLanguage)}
                         onChange={(e) => handleTermChange(term._index, 'target', e.target.value)}
                         disabled={isUpdating}
                         placeholder={t('glossaries.detail.targetPlaceholder') || 'terme cible'}
diff --git a/frontend/src/lib/i18n.tsx b/frontend/src/lib/i18n.tsx
index a5f17f5..fd4e585 100644
--- a/frontend/src/lib/i18n.tsx
+++ b/frontend/src/lib/i18n.tsx
@@ -438,6 +438,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -1425,6 +1426,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirmer la suppression ?",
     "glossaries.detail.confirm": "Confirmer",
     "glossaries.detail.cancel": "Annuler",
+    "glossaries.detail.sourceLangNote": "'La source originale est en francais. Pour les autres langues, on lit le champ translations du terme (si disponible).'",
     "glossaries.detail.sourceLocked": "fixé",
     "glossaries.detail.sourceLockedNote": "Les templates ne stockent la source qu'en français. Le multilingue source est sur la roadmap.",
     "glossaries.detail.targetLangNote": "Choisissez une langue pour voir les traductions correspondantes, ou « Multilingue » pour la valeur par défaut.",
@@ -2398,6 +2400,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -3326,6 +3329,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -4254,6 +4258,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -5182,6 +5187,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -6110,6 +6116,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -7038,6 +7045,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -7968,6 +7976,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -8895,6 +8904,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -9822,6 +9832,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -10707,6 +10718,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",
@@ -11601,6 +11613,7 @@ const messages: Record<Locale, Record<string, string>> = {
     "glossaries.detail.confirmDelete": "Confirm deletion?",
     "glossaries.detail.confirm": "Confirm",
     "glossaries.detail.cancel": "Cancel",
+    "glossaries.detail.sourceLangNote": "'The original source is in French. For other languages, we read the term's translations field (if available).'",
     "glossaries.detail.sourceLocked": "fixed",
     "glossaries.detail.sourceLockedNote": "Templates only store the source in French. Multilingual source is on the roadmap.",
     "glossaries.detail.targetLangNote": "Pick a language to see the matching translations, or « Multilingual » for the default value.",