insect

Etymology

From Middle French insecte, from Latin īnsectum, from īnsectus (“cut into, cut up, with a notched or divided body”), from perfect passive participle of īnsecō (“I cut into, I cut up”), from in- + secō (“I cut”), from the notion that the insect's body is "cut into" three sections (head, thorax, abdomen). Calque of Ancient Greek ἔντομον (éntomon, “insect”), from ἔντομος (éntomos, “cut into pieces”).

noun

1. An arthropod (in the Insecta class) characterized by six legs, up to four wings, and a chitinous exoskeleton.
   Our shed has several insect infestions, including ants, yellowjackets, and wasps.
   Nonetheless, some insect prey take advantage of clutter by hiding in it. Earless ghost swift moths become “invisible” to echolocating bats by forming mating clusters close (less than half a meter) above vegetation and effectively blending into the clutter of echoes that the bat receives from the leaves and stems around them. 2013 May-June, William E. Conner, “An Acoustic Arms Race”, in American Scientist, volume 101, number 3, pages 206–7
2. (colloquial) Any small arthropod similar to an insect, including spiders, centipedes, millipedes, etc.
   The swamp is swarming with every sort of insect.
3. (derogatory) A contemptible or powerless person.
   The manager’s assistant was the worst sort of insect.