Definition of: metencephalon

(met′ən·sef′ə·lən) noun plural ·la (-lə) Anat.
1. The fifth cerebral vesicle of the brain and the parts derived therefrom, comprising the medulla oblongata and the posterior part of the roof of the fourth ventricle.
2. The part of the brain consisting of the cerebellum and pons Varolii. [<NL <MET- + ENCEPHALON]
—met′en·ce·phal′ic (-sə·fal′·ik) adjective