allis shad vs shad

allis shad and shad both are nouns.

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

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

allis shad: European shad
shad: herring-like food fishes that migrate from the sea to fresh water to spawn

allis shad (noun)	shad (noun)
European shad	herring-like food fishes that migrate from the sea to fresh water to spawn
	bony flesh of herring-like fish usually caught during their migration to fresh water for spawning; especially of Atlantic coast