cerebellum

n. lower back portion of the brain

The cerebellum (Latin: "little brain") is a region of the brain that plays an important role in the integration of sensory perception and motor output. Many neural pathways link the cerebellum with the motor cortex—which sends information to the muscles causing them to move—and the spinocerebellar tract—which provides feedback on the position of the body in space (proprioception). The cerebellum integrates these pathways, using the constant feedback on body position to fine-tune motor movements.
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Cerebellum /cer·e·bel·lum/ the part of the metencephalon situated on the back of the brain stem, to which it is attached by three cerebellar [more]Cerebellum - Community and Resources

Noun
1. a major division of the vertebrate brain; situated above the medulla oblongata and beneath the cerebrum in humans
(hypernym) neural structure
(part-holonym) hindbrain, rhombencephalon
(part-meronym) cerebellar artery, arteria cerebelli

n. cerebellum, lower back portion of the brain