shad vs clupeid

shad and clupeid both are nouns.

Word	Noun	Adjective	Verb	Adverb
shad	Yes	No	No	No
clupeid	Yes	No	No	No

As nouns, clupeid is a hypernym of shad; that is, clupeid is a word with a broader meaning than shad:

shad: herring-like food fishes that migrate from the sea to fresh water to spawn
clupeid: any of numerous soft-finned schooling food fishes of shallow waters of northern seas

Other hypernyms of shad include food fish, clupeid fish.

shad (noun)	clupeid (noun)
herring-like food fishes that migrate from the sea to fresh water to spawn	any of numerous soft-finned schooling food fishes of shallow waters of northern seas
bony flesh of herring-like fish usually caught during their migration to fresh water for spawning; especially of Atlantic coast