\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. See
{Darter}.