The Collaborative International Dictionary of English v.0.48:

Cerebrum \Cer"e*brum\, n.; pl. E. Cerebrums, L. Cerebra.
   [L., the brain.] (Anat.)
   The anterior, and in man the larger, division of the brain;
   the seat of the reasoning faculties and the will. See
   Brain.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cerebrum
    n 1: anterior portion of the brain consisting of two
         hemispheres; dominant part of the brain in humans