/ Dictionary / Index R rainbow darter: Meaning and Definition of Find definitions for: rain'bow dart"er Pronunciation: [key] a stout darter, Etheostoma caeruleum, inhabiting the Great Lakes and Mississippi River drainages, the spawning male of which has the sides marked with oblique blue bars with red interspaces. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rainbow-collar rainbow fish Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language