kneecap vs sesamoid bone

kneecap and sesamoid bone both are nouns.

Word	Noun	Adjective	Verb	Adverb
kneecap	Yes	No	Yes	No
sesamoid bone	Yes	No	No	No

As nouns, sesamoid bone is a hypernym of kneecap; that is, sesamoid bone is a word with a broader meaning than kneecap:

kneecap: a small flat triangular bone in front of the knee that protects the knee joint
sesamoid bone: any of several small round bones formed in a tendon where it passes over a joint

Other hypernyms of kneecap include os sesamoideum, sesamoid.

kneecap (noun)	sesamoid bone (noun)
a small flat triangular bone in front of the knee that protects the knee joint	any of several small round bones formed in a tendon where it passes over a joint

kneecap (verb)	sesamoid bone (verb)
shoot in the kneecap, often done by terrorist groups as a warning