hornet (n.) Look up hornet at Dictionary.com
Old English hyrnet, hurnitu "large wasp, beetle, gadfly," probably from Proto-Germanic *hurz-nut- (cognates: 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 szirszu "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.