c.1600, from L. (animal) insectum "(animal) with a notched or divided body," lit. "cut into," from neuter pp. of insectare "to cut into, to cut up," from in- "into" (see in- (2)) + secare "to cut" (see section). Pliny's loan-translation of Gk. entomon "insect" (see entomology), which was Aristotle's term for this class of life, in reference to their "notched" bodies. First in English in 1601 in Holland's translation of Pliny. Translations of Aristotle's term also form the usual word for "insect" in Welsh (trychfil, from trychu "cut" + mil "animal"), Serbo-Croatian (zareznik, from rezati "cut"), Russian (nasekomoe, from sekat "cut"), etc.
