a. Zool. [f. mod.L. Lyencephal-a (Owen) + -OUS.
According to Owen himself (Classif. Mammalia, 1859), his term Lyencephala is f. Gr. λύ-ειν to loose + ἐγκέφαλος brain (see ENCEPHALON), and signifies ‘the comparatively loose or disconnected state of the cerebral hemispheres.’]
Of or belonging to the Lyencephala, in Owen’s classification the lowest group of Mammals, including the Monotremes and the Marsupials.
1859. Owen, Classif. Mammalia, 27. The Lyencephalous Mammalia.
1864. in Webster. And in later Dicts.
