Definition of "forebrain" [fore•brain]

• The most anterior of the three primary regions of the embryonic brain from which the telencephalon and diencephalon develop. (noun)
• The segment of the adult brain that develops from the embryonic forebrain and includes the cerebrum, thalamus, and hypothalamus. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In reading, one's forebrain is fully engaged; when it disengages, reading stops."
• "New research finds that nitric oxide accumulation in the brain's basal forebrain is both necessary and sufficient to produce sleep, providing a completely new basis for developing drugs that help people stay awake -- or, conversely, sleep."
• ""It seems that now, finally, recognition has arrived at Werner Herzog's feet, and for an inveterate, lifelong Herzogian (alright, since adolescence), his current presence in the cultural forebrain is something of a vindication.""