Definition of insect

• n. - One of the Insecta; esp., one of the Hexapoda. See Insecta.
• n. - Any air-breathing arthropod, as a spider or scorpion.
• n. - Any small crustacean. In a wider sense, the word is often loosely applied to various small invertebrates.
• n. - Fig.: Any small, trivial, or contemptible person or thing.
• a. - Of or pertaining to an insect or insects.
• a. - Like an insect; small; mean; ephemeral.