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posterior

American  
[po-steer-ee-er, poh-] / pɒˈstɪər i ər, poʊ- /

adjective

  1. situated behind or at the rear of; hinder (opposed to anterior).

  2. coming after in order, as in a series.

  3. coming after in time; later; subsequent (sometimes followed byto ).

  4. Anatomy, Zoology.

    1. (in quadrupeds) pertaining to or toward the rear or caudal end of the body.

    2. (in humans and other primates) pertaining to or toward the back plane of the body, equivalent to the dorsal surface of quadrupeds.

  5. Botany. toward the back and near the main axis, as the upper lip of a flower.


noun

  1. the hinder parts or rump of the body; buttocks.

posterior British  
/ pɒˈstɪərɪə /

adjective

  1. situated at the back of or behind something

  2. coming after or following another in a series

  3. coming after in time

  4. zoology (of animals) of or near the hind end

  5. botany (of a flower) situated nearest to the main stem

  6. anatomy dorsal or towards the spine

"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

noun

  1. the buttocks; rump

  2. statistics a posterior probability

"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

Related Words

See back 1.

Other Word Forms

Etymology

Origin of posterior

1525–35; < Latin, comparative of posterus coming after, derivative of post after

Explanation

Use the adjective posterior to describe something that's in the back. It’s often used in anatomy — a posterior cerebral artery supplies blood to the back of the brain, and the tail is on the posterior of a fish. The prefix post means “after,” and things that are posterior come after the things in the front. The opposite of posterior is anterior, which refers to the front, usually of body parts. You can also use the word posterior to jokingly refer to the part of your body that you sit on — your backside. Posterior is also a formal way to say later in time.

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Vocabulary lists containing posterior

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.

To offset that, he pays extra attention to strengthening the posterior, or back, chain of their bodies.

From Los Angeles Times • Jan. 1, 2026

Scientists have long proposed, including Sur's colleague Earl K. Miller at MIT, that the prefrontal cortex can guide the activity of more posterior areas of the brain.

From Science Daily • Nov. 30, 2025

As a parent, the first time I saw one of my sons talk out of their posterior on a subject they knew nothing about, I laughed.

From Salon • Oct. 24, 2025

Dr. Keith Meister performed the surgery in Arlington, Texas, to repair what Hollander described as a small tear in the posterior of Brash’s ulnar collateral ligament.

From Seattle Times • May 10, 2024

At one end sat Chiron the centaur, his equine posterior collapsed into his magic wheelchair so he looked like a regular human.

From "Blood of Olympus" by Rick Riordan

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