forebrain

American  

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

noun

Anatomy.

1. 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.

2. the telencephalon.

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forebrain British  

/ ˈfɔːˌbreɪn /

noun

1. the nontechnical name for prosencephalon

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forebrain Scientific  

/ fôr′brān′ /

1. The forwardmost part of the vertebrate brain. In humans, it consists of the thalamus, the hypothalamus, and the cerebrum.

2. Compare hindbrain midbrain

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Etymology

Origin of forebrain

First recorded in 1875–80; fore- + brain

Example Sentences

GLP-1 receptor agonists suppress thirst as well as appetite, and a region in the forebrain of rats called the median preoptic area appears to be involved in this effect.

From Science Daily • Nov. 18, 2025

This technical advance allowed them to identify previously unseen pathways connecting the brainstem, thalamus, hypothalamus, basal forebrain, and cerebral cortex.

From Science Daily • May 1, 2024

The neuron density of its forebrain — the region engaged with planning, sensory processing, and emotional responses, and on which REM sleep is largely dependent — is comparable to that of primates.

From New York Times • Mar. 26, 2024

In this week’s issue of Cell, a research team in Europe reports using fetal brain tissue to grow 3D structures that resemble those that naturally occur in the cortex, forebrain, or spinal cord.

From Science Magazine • Jan. 10, 2024

There were the cerebral lobes, or largest part of the forebrain, enormously developed and overhanging the cerebellum, or great lobe of the hindbrain, and completely covering the lobes of the midbrain.

From Byways of Ghost-Land by O'Donnell, Elliott