diff --git a/src/core/Synset.test.ts b/src/core/Synset.test.ts
index 71239d0..3bbb07d 100644
--- a/src/core/Synset.test.ts
+++ b/src/core/Synset.test.ts
@@ -149,6 +149,18 @@ describe('Synset', () => {
     });
   });
 
+  describe('.size', () => {
+    it('should return lemma count', () => {
+      const synset = anEmptySynset();
+      expect(synset.size).toBe(0);
+      synset.add(new LemmaGroup());
+      synset.add(new LemmaGroup());
+      expect(synset.size).toBe(0);
+      synset.add(['some1', 'some2']);
+      expect(synset.size).toBe(2);
+    });
+  });
+
   describe('.union()', () => {
     it('should create a new synset with all the values', () => {
       const synset1 = anEmptySynset().add(['a', 'b']);
diff --git a/src/core/Synset.ts b/src/core/Synset.ts
index 726c9fa..08e9cdf 100644
--- a/src/core/Synset.ts
+++ b/src/core/Synset.ts
@@ -108,6 +108,10 @@ export class Synset {
     return !!this.lemmas().next().done;
   }
 
+  public get size(): number {
+    return [...this.lemmas()].length;
+  }
+
   public union(
     other: Synset,
     equals: EqualityPredicate<Lemma> = valueEquals,