Macrocephalous \Mac`ro*ceph"a*lous\, a. [Macro + Gr. kefalh` the head.] 1. Having a large head. 2. (Bot.) Having the cotyledons of a dicotyledonous embryo confluent, and forming a large mass compared with the rest of the body. --Henslow.
macrocephalous adj : having an exceptionally large head and brain [syn: {macrocephalic}]