Source : Webster's Revised Unabridged Dictionary (1913)

Gyrencephala \Gyr"en*ceph`a*la\, n. pl. [NL. fr. Gr. ? round+ ?
   the brain.] (Zo["o]l.)
   The higher orders of Mammalia, in which the cerebrum is
   convoluted. -- {Gyr"en*ceph"a*lous}, a.