porc vs pigs' knuckles

porc and pigs' knuckles both are nouns.

Word	Noun	Adjective	Verb	Adverb
porc	Yes	No	No	No
pigs' knuckles	Yes	No	No	No

As nouns, pigs' knuckles is a hyponym of porc; that is, pigs' knuckles is a word with a more specific, narrower meaning than porc:

porc: meat from a domestic hog or pig
pigs' knuckles: feet or knuckles of hogs used as food; pickled or stewed or jellied

Other hyponyms of porc include cochon de lait, suckling pig, salt pork, pigs' feet.

porc (noun)	pigs' knuckles (noun)
meat from a domestic hog or pig	feet or knuckles of hogs used as food; pickled or stewed or jellied