wood louse vs isopod

wood louse and isopod both are nouns.

Word	Noun	Adjective	Verb	Adverb
wood louse	Yes	No	No	No
isopod	Yes	No	No	No

As nouns, isopod is a hypernym of wood louse; that is, isopod is a word with a broader meaning than wood louse:

wood louse: any of various small terrestrial isopods having a flat elliptical segmented body; found in damp habitats
isopod: any of various small terrestrial or aquatic crustaceans with seven pairs of legs adapted for crawling

wood louse (noun)	isopod (noun)
any of various small terrestrial isopods having a flat elliptical segmented body; found in damp habitats	any of various small terrestrial or aquatic crustaceans with seven pairs of legs adapted for crawling