flounder vs plaice

flounder and plaice both are nouns.

Word	Noun	Adjective	Verb	Adverb
flounder	Yes	No	Yes	No
plaice	Yes	No	No	No

As nouns, plaice is a hyponym of flounder; that is, plaice is a word with a more specific, narrower meaning than flounder:

Other hyponyms of flounder include yellowtail flounder, turbot, sand dab, lemon sole, winter flounder.

flounder (noun)	plaice (noun)
any of various European and non-European marine flatfish	large European food fish
flesh of any of various American and European flatfish	flesh of large European flatfish

flounder (verb)	plaice (verb)
walk with great difficulty
behave awkwardly; have difficulties