[ fawr-breyn, fohr- ]
/ ˈfɔrˌbreɪn, ˈfoʊr- /

noun Anatomy.

Also called prosencephalon. the anterior of the three primary divisions of the brain in the embryo of a vertebrate, or the part of the adult brain derived from this tissue including the diencephalon and telencephalon.
the telencephalon.

Origin of forebrain

First recorded in 1875–80; fore- + brain Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for forebrain

  • Autopsies on imbeciles show an infantile development of the forebrain.

  • He jerked his mind away suddenly from the thoughts which had crowded into his forebrain.

    Cum Grano Salis|Gordon Randall Garrett
  • The molecules mingle with the molecules of serum: In seconds they are washed against the cell-walls of the forebrain.

    The Syndic|C.M. Kornbluth

British Dictionary definitions for forebrain

/ (ˈfɔːˌbreɪn) /


the nontechnical name for prosencephalon
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for forebrain

[ fôrbrān′ ]


The prosencephalon.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for forebrain

[ fôrbrān′ ]

The forwardmost part of the vertebrate brain. In humans, it consists of the thalamus, the hypothalamus, and the cerebrum. Compare hindbrain midbrain.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.