insectn.[F. insecte, L. insectum, fr. insectus, p. p. of insecare to cut in. See Section. The name was originally given to certain small animals, whose bodies appear cut in, or almost divided. Cf. Entomology.]1. (Zol.) One of the Insecta; esp., one of the Hexapoda. See Insecta.()()2. (Zol.) Any air-breathing arthropod, as a spider or scorpion.()3. (Zol.) Any small crustacean. In a wider sense, the word is often loosely applied to various small invertebrates.()4. Fig.: Any small, trivial, or contemptible person or thing.(Thomson.)Insect powder,a powder used for the extermination of insects; esp., the powdered flowers of certain species of Pyrethrum, a genus now merged in Chrysanthemum. Called also Persian powder.()a.1. Of or pertaining to an insect or insects.()2. Like an insect; small; mean; ephemeral.()