- the left hemisphere of the human brain, which is believed to control linear and analytical thinking, decision-making, and language
- (as modifier): a left-brain activity
WordReference Random House Unabridged Dictionary of American English © 2015
Anatomythe cerebral hemisphere on the left side of the corpus callosum, controlling activity on the right side of the body: in humans, usually showing some degree of specialization for language and calculation. Cf. right brain.