pelecypod vs scollop

pelecypod and scollop both are nouns.

Word	Noun	Adjective	Verb	Adverb
pelecypod	Yes	Yes	No	No
scollop	Yes	No	Yes	No

As nouns, scollop is a hyponym of pelecypod; that is, scollop is a word with a more specific, narrower meaning than pelecypod:

pelecypod: marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
scollop: edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions

Other hyponyms of pelecypod include clam, cockle, oyster, ark shell, blood clam, mussel, escallop, scallop, piddock.

pelecypod (noun)	scollop (noun)
marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together	edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions
	edible muscle of mollusks having fan-shaped shells; served broiled or poached or in salads or cream sauces
	thin slice of meat (especially veal) usually fried or broiled

pelecypod (adjective)	scollop (adjective)
bivalve