The Collaborative International Dictionary
Etheostomoid \E`the*os"to*moid\, a. [NL. etheostoma name of a genus + -oid.] (Zo["o]l.) Pertaining to, or like, the genus Etheostoma. -- n. Any fish of the genus Etheostoma and related genera, allied to the perches; -- also called darter. The etheostomoids are small and often bright-colored fishes inhabiting the fresh waters of North America. About seventy species are known, including the rare snail darter ( Percina tanasi), 3 inches long, found only in the Tennessee River and classified as a threatened species. See Darter.
Wiktionary
a. (context zoology English) Resembling or relating to the genus ''Etheostoma'' of fishes allied to the perch. n. (context zoology English) Any of the fish of ''Etheostoma'' and related genus.