/ Dictionary / Index L least killifish: Meaning and Definition of Find definitions for: least' kil'lifish Pronunciation: [key] a fish, Heterandria formosa, of coastal swamps from South Carolina to Florida, that feeds on mosquito larvae. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. least flycatcher least sandpiper Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language