putamen

noun

1. The shell of a nut; the stone of a drupe fruit; endocarp.
2. A round structure located at the base of the forebrain, regulating movement and learning.

   “For calculation of D2 BP, bilateral caudate and putamen ROIs were defined anatomically.”

   “[M]ultilingual speakers have a greater density of grey matter in the area involved in articulation and phonological processes, namely the left putamen.”