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midbrain

American  
[mid-breyn] / ˈmɪdˌbreɪn /

noun

Anatomy.

  1. the middle 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; mesencephalon.

midbrain British  
/ ˈmɪdˌbreɪn /

noun

  1. the nontechnical name for mesencephalon

"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
midbrain Scientific  
/ mĭd′brān′ /

  1. The middle part of the vertebrate brain. In most animals except mammals, the midbrain processes sensory information. In mammals, it serves primarily to connect the forebrain with the hindbrain.

  2. Compare forebrain hindbrain

Etymology

Origin of midbrain

First recorded in 1870–75; mid- + brain

Vocabulary lists containing midbrain

Florida's B.E.S.T. Common Prefixes: mid-

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

This "comprehensive reference map" now serves as a global standard for evaluating how accurately midbrain models match real human biology.

From Science Daily • Nov. 3, 2025

Researchers then had the same bats repeat the task but with a critical auditory pathway in the midbrain temporarily blocked.

From Science Daily • Nov. 25, 2024

As a result, the system organized itself to mimic the forebrain, midbrain, hindbrain and spinal cord in a way that mirrors embryonic development.

From Science Daily • Feb. 26, 2024

Analyzing the aquatically loquacious may also give us clues about whether midbrain injuries in humans may be linked to a person being mute or uncommunicative, according to Bass.

From Salon • Jan. 8, 2024

In reflex action the impulses are mainly through the spinal cord, but to some extent through the bulb, pons, and midbrain.

From Physiology and Hygiene for Secondary Schools by Walters, Francis M.

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.