cartilage vs gristle

cartilage and gristle both are nouns.

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

As nouns, cartilage and gristle are synonyms defined as:

cartilage and gristle: tough elastic tissue; mostly converted to bone in adults

cartilage (noun)	gristle (noun)
tough elastic tissue; mostly converted to bone in adults	tough elastic tissue; mostly converted to bone in adults