noun
Etymology: Middle English ston flye, from ston stone + flye fly — more at stone , fly
: any of numerous insects constituting the order Plecoptera, having two pairs of membranous wings with the hinder pair folded in plaits and lying upon the abdomen when at rest, a large free prothorax, and long antennae and cerci, and characterized by an incomplete metamorphosis in which the nymphs are carnivorous, aquatic, and furnished with gills