The Collaborative International Dictionary
Lissencephala
Lissencephala \Lis`sen*ceph"a*la\ (l[i^]s`s[e^]n*s[e^]f"[.a]*l[.a]), n. pl. [NL., fr. Gr. lisso`s smooth + 'egke`falos the brain.] (Zo["o]l.) A general name for all those placental mammals that have a brain with few or no cerebral convolutions, as Rodentia, Insectivora, etc.