soft-shell clam vs clam

soft-shell clam and clam both are nouns.

Word	Noun	Adjective	Verb	Adverb
soft-shell clam	Yes	No	No	No
clam	Yes	No	Yes	No

As nouns, clam is a hypernym of soft-shell clam; that is, clam is a word with a broader meaning than soft-shell clam:

soft-shell clam: an edible clam with thin oval-shaped shell found in coastal regions of the United States and Europe
clam: burrowing marine mollusk living on sand or mud; the shell closes with viselike firmness

As nouns, clam is a hypernym of soft-shell clam; that is, clam is a word with a broader meaning than soft-shell clam:

soft-shell clam (noun)	clam (noun)
an edible clam with thin oval-shaped shell found in coastal regions of the United States and Europe	burrowing marine mollusk living on sand or mud; the shell closes with viselike firmness
a clam that is usually steamed in the shell	flesh of either hard-shell or soft-shell clams
	a piece of paper money worth one dollar

soft-shell clam (verb)	clam (verb)
	gather clams, by digging in the sand by the ocean