The Collaborative International Dictionary of English v.0.48:
Hindbrain \Hind"brain`\, n. [Hind, adj. + brain.] (Anat.) The posterior of the three principal divisions of the brain, including the epencephalon and metencephalon. Sometimes restricted to the epencephalon only. [1913 Webster]WordNet (r) 3.0 (2006):
hindbrain n 1: the posterior portion of the brain including cerebellum and brainstem [syn: hindbrain, rhombencephalon]