diff --git a/kjvstudy_org/jinja_filters.py b/kjvstudy_org/jinja_filters.py
index 4799697..f779963 100644
--- a/kjvstudy_org/jinja_filters.py
+++ b/kjvstudy_org/jinja_filters.py
@@ -147,7 +147,11 @@ def link_verse_references_in_text(text):
 
 
 def inject_word_markers(text, word_studies, verse_num):
-    """Inject sidenote markers into verse text next to annotated words"""
+    """Inject sidenote markers into verse text next to annotated words.
+
+    Word studies are collapsed by default, showing only the word and Greek/Hebrew term.
+    Clicking expands to show transliteration and full definition.
+    """
     if not word_studies:
         return text
 
@@ -159,7 +163,15 @@ def inject_word_markers(text, word_studies, verse_num):
             term_html = f'<a href="/strongs/{strongs}">{study["term"]}</a>'
         else:
             term_html = study["term"]
-        marker = f'<label for="sn-{verse_num}-word-{idx}" class="margin-toggle sidenote-number"></label><input type="checkbox" id="sn-{verse_num}-word-{idx}" class="margin-toggle"/><span class="sidenote"><strong>{word}:</strong> {term_html} (<em>{study["translit"]}</em>). {study["note"]}</span>'
+        # Wrap details (translit + note) in a span that's hidden by default
+        marker = (
+            f'<label for="sn-{verse_num}-word-{idx}" class="margin-toggle sidenote-number"></label>'
+            f'<input type="checkbox" id="sn-{verse_num}-word-{idx}" class="margin-toggle"/>'
+            f'<span class="sidenote word-study">'
+            f'<strong>{word}:</strong> {term_html}'
+            f'<span class="word-study-details"> (<em>{study["translit"]}</em>). {study["note"]}</span>'
+            f'</span>'
+        )
         pattern = re.compile(r'\b(' + re.escape(word) + r')(?!\'[sS])\b', re.IGNORECASE)
         text = pattern.sub(r'\1' + marker, text, count=1)
 
diff --git a/kjvstudy_org/templates/chapter.html b/kjvstudy_org/templates/chapter.html
index e3d72d7..6a6e8dc 100644
--- a/kjvstudy_org/templates/chapter.html
+++ b/kjvstudy_org/templates/chapter.html
@@ -101,6 +101,32 @@
     margin-bottom: 1rem;
 }
 
+/* Word studies: collapsed by default, show only word + Greek term */
+.sidenote.word-study {
+    max-height: none;
+    overflow: visible;
+    cursor: pointer;
+}
+
+.sidenote.word-study .word-study-details {
+    display: none;
+}
+
+.sidenote.word-study.expanded .word-study-details {
+    display: inline;
+}
+
+/* Show expand indicator for collapsed word studies */
+.sidenote.word-study:not(.expanded)::after {
+    content: " ▸";
+    font-size: 0.8em;
+    color: var(--text-secondary);
+}
+
+.sidenote.word-study.expanded::after {
+    content: "";
+}
+
 @media (max-width: 760px) {
     .sidenote,
     .marginnote {