[ stohn-flahy ]
/ ˈstoʊnˌflaɪ /

noun, plural stone·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, especially bass and trout, which makes them popular as models for fishing flies.

Origin of stonefly

First recorded in 1400–50, stonefly is from the late Middle English word ston flie. See stone, fly2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for stonefly

/ (ˈstəʊnˌflaɪ) /

noun plural -flies

any insect of the order Plecoptera, in which the larvae are aquatic, living beneath stones, and the adults have long antennae and two pairs of large wings and occur near water

Word Origin for stonefly

C15: so called because its larvae live under stones in rivers
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012