n.
an arthropod animal of a large class (Insecta) having a head, thorax, and abdomen, six legs, two antennae, and one or two pairs of wings.
▸informal any small invertebrate animal such as a spider or tick.
Etymology
C17: from L. (animal) insectum ‘segmented (animal)’ (translating Gk zōion entomon), from insecare ‘cut up or into’.