/ Dictionary / Index S stonefly: Meaning and Definition of Find definitions for: stone•fly Pronunciation: (stōn'flī"), [key] — pl. -flies. any of numerous dull-colored primitive aquatic insects of the order Plecoptera, having a distinctive flattened body shape: a major food source for game fish, esp. bass and trout, which makes them popular as models for fishing flies. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: stonefly (Thesaurus) stonefish stone fruit Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language