an insect of the order Hymenoptera, usually with a hard shiny body, usually with biting mouthparts, and a predatory or parasitic life style
A wasp is any insect of the order Hymenoptera and suborder Apocrita that is not a bee or an ant. Less familiar, the suborder Symphyta includes the sawflies and wood wasps, which differ from the Apocrita by having a broad connection between the thorax and abdomen. Also, Symphyta larvae are mostly herbivorous and "caterpillarlike", whereas those of Apocrita are largely predatory or "parasitic" (actually more technically known as parasitoid).