semilunar cartilage vs gristle

semilunar cartilage and gristle both are nouns.

Word	Noun	Adjective	Verb	Adverb
semilunar cartilage	Yes	No	No	No
gristle	Yes	No	No	No

As nouns, gristle is a hypernym of semilunar cartilage; that is, gristle is a word with a broader meaning than semilunar cartilage:

semilunar cartilage: (anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint
gristle: tough elastic tissue; mostly converted to bone in adults

Other hypernyms of semilunar cartilage include cartilage.

semilunar cartilage (noun)	gristle (noun)
(anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint	tough elastic tissue; mostly converted to bone in adults