hornet (n.)

Old English hyrnet, hurnitu "large wasp, beetle, gadfly," probably from Proto-Germanic *hurz-nut- (source also of Old Saxon hornut; Middle Dutch huersel, Dutch horzel (with diminutive suffix); Old High German hornaz, German Hornisse "hornet"), from a PIE imitative (buzzing) root; compare Old Church Slavonic srusa, Lithuanian širšu "wasp." On this theory, the English word (as well as German Hornisse) was altered by influence of horn, to suggest either "horner" (from the sting) or "horn-blower" (from the buzz). Compare also Old Saxon hornobero "hornet," literally "trumpeter." Figurative of troublesome and persistent attacks.