Plethodontidae vs plethodont

Plethodontidae and plethodont both are nouns.

Word	Noun	Adjective	Verb	Adverb
Plethodontidae	Yes	No	No	No
plethodont	Yes	No	No	No

Plethodontidae (noun)	plethodont (noun)
small mostly terrestrial New World salamanders having neither lungs nor gills as adults	mostly terrestrial salamanders that breathe through their thin moist skin; lay eggs in moist places on land; rarely enter water