meniscus vs gristle

meniscus and gristle both are nouns.

Word	Noun	Adjective	Verb	Adverb
meniscus	Yes	No	No	No
gristle	Yes	No	No	No

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

meniscus: (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 meniscus include cartilage.

meniscus (noun)	gristle (noun)
(physics) the curved upper surface of a nonturbulent liquid in a vertical tube	tough elastic tissue; mostly converted to bone in adults
(optics) a lens that is concave on one side and convex on the other
(anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint