pigs' knuckles vs pigs' feet

pigs' knuckles and pigs' feet both are nouns.

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

As nouns, pigs' knuckles and pigs' feet are synonyms defined as:

pigs' knuckles and pigs' feet: feet or knuckles of hogs used as food; pickled or stewed or jellied

pigs' knuckles (noun)	pigs' feet (noun)
feet or knuckles of hogs used as food; pickled or stewed or jellied	feet or knuckles of hogs used as food; pickled or stewed or jellied