Coleoptera :: Coleoptera (n. pl.) An order of insects having the anterior pair of wings (elytra) hard and horny, and serving as coverings for the posterior pair, which are membranous, and folded transversely under the others when not in use. The mouth parts form two pairs of jaws (mandibles and maxillae) adapted for chewing. Most of the Coleoptera are known as beetles and weevils..