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

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "cerebrum":
   arachnoid, arbor vitae, archipallium, between brain, brain stem,
   cerebellar hemispheres, cerebellum, cerebral cortex,
   cerebrospinal fluid, convolution, corpus callosum, corpus striatum,
   diencephalon, dura mater, endbrain, fissure, folia, forebrain,
   fornix, frontal lobe, glial cells, globus pallidus, gray matter,
   gyrus, hindbrain, hippocampus, hypothalamus, lenticular nucleus,
   limbic lobe, little brain, lobe, mantle, medulla oblongata,
   meninges, mesencephalon, metencephalon, midbrain, myelencephalon,
   neopallium, occipital lobe, optic chiasm, pallium, parietal lobe,
   pia mater, pineal body, pituitary body, pons, reticular system,
   rhombencephalon, subthalamus, telencephalon, temporal lobe,
   thalamus, ventricle, vermis, white matter