crawdad vs decapod crustacean

crawdad and decapod crustacean both are nouns.

Word	Noun	Adjective	Verb	Adverb
crawdad	Yes	No	No	No
decapod crustacean	Yes	No	No	No

As nouns, decapod crustacean is a hypernym of crawdad; that is, decapod crustacean is a word with a broader meaning than crawdad:

crawdad: small freshwater decapod crustacean that resembles a lobster
decapod crustacean: crustaceans characteristically having five pairs of locomotor appendages each joined to a segment of the thorax

Other hypernyms of crawdad include decapod.

crawdad (noun)	decapod crustacean (noun)
small freshwater decapod crustacean that resembles a lobster	crustaceans characteristically having five pairs of locomotor appendages each joined to a segment of the thorax
tiny lobster-like crustaceans usually boiled briefly