basal ganglia

noun Anatomy.

1. any of several masses of gray matter in each cerebral hemisphere.

pl n

1. the thalamus together with other closely related masses of grey matter, situated near the base of the brain

pl.n.

1. The caudate and lentiform nuclei of the brain and the cell groups associated with them, considered as a group.
2. All of the large masses of gray matter at the base of the cerebral hemisphere. No longer in technical use.