Chaos (Gr. from to gape, to open widely), in classical mythology, either the empty and infinite space which existed before all things or the mixture of all the elements, the confused mass out of which the ordered creation was formed. By the poets Chaos was personified and made the most ancient of the gods, the father of Erebus and Night. The principle of the fecundity of chaos assumed several modifications in the Greek systems of philosophy. Something similar to the Greek conception of chaos is found in the Phoenician, Chaldean, and Indian cosmogonies; and Ovid's description of the genesis of the universe out of chaos has so many features in common with the Mosaic account of creation, that it has often been supposed to have been derived from it. - In natural history, chaos is the name given by Linnaeus to animals and plants of the lowest orders, which have imperfect parts.