One of the Insecta; esp., one of the Hexapoda. See Insecta.
- Any of numerous usually small arthropod animals of the class Insecta, having an adult stage characterized by three pairs of legs and a body segmented into head, thorax, and abdomen and usually having two pairs of wings. Insects include the flies, crickets, mosquitoes, beetles, butterflies, and bees.
- Any of various similar arthropod animals, such as spiders, centipedes, or ticks. See Regional Note at lightning bug.
- An insignificant or contemptible person.