the earth-worm, in zoology, a genus of insects belonging to the order of vermes intestina. The body is cylindrical, annulated, with an elevated belt near the middle. There is but one species of this animal. It lives underground, and feeds upon the roots and seeds of plants. It comes above ground in the night, or during rain, for the purpose of copulation. For the effects of these animals in the human body, and the method of expelling them, see (the Index subjoined to) Medicine.