pro·tru·sion | \prō-ˈtrü-zhən \

Definition of protrusion 

1 : the act of protruding : the state of being protruded

2 : something (such as an anatomical part or excrescence) that protrudes

Keep scrolling for more

Choose the Right Synonym for protrusion

projection, protrusion, protuberance, bulge mean an extension beyond the normal line or surface. projection implies a jutting out especially at a sharp angle. those projections along the wall are safety hazards protrusion suggests a thrusting out so that the extension seems a deformity. the bizarre protrusions of a coral reef protuberance implies a growing or swelling out in rounded form. a skin disease marked by warty protuberances bulge suggests an expansion caused by internal pressure. bulges in the tile floor

Examples of protrusion in a Sentence

bony protrusions on the outside of the elbow a roof with many protrusions The pain was caused by a protrusion of a disc in his lower back.
See More

Recent Examples on the Web

Those protrusions are topped by a ring of string-like filaments. David Grossman, Popular Mechanics, "New Tardigrade Species Found in Parking Lot," 28 Feb. 2018 Moth tails vary from species to species: Some have big lobes at the bottom of the hindwing instead of a distinctive tail; others have just a short protrusion. Elizabeth Pennisi, Science | AAAS, "Watch how battles with bats give moths their flashy tails," 4 July 2018 Cardboard protrusions on the motorbike controller can push buttons on the Joy-Cons to activate items, braking, and drifting. Kyle Orland, Ars Technica, "You can now play Mario Kart 8 with Labo’s cardboard motorbike controller," 26 June 2018 Pachycephalosaurus had a thick, bony skull with all kinds of jagged protrusions, the better to fight its rivals with. Emma Stefansky, GQ, "The Definitive Jurassic Park Dinosaur Power Rankings," 21 June 2018 These big-ledged protrusions from the cliff top reveal panoramas that seem to stretch forever. Roger Naylor, azcentral, "Cool off this summer at these lakes near Payson," 8 June 2018 Cerebrospinal fluid is produced continuously in the brain and is normally absorbed into the bloodstream through protrusions in the outer membrane of the brain, called the dura mater. Mark Lieber, CNN, "Woman's runny nose was actually fluid from inside her brain," 8 May 2018 The restaurant is a long, rectangular stucco building, tan all over except for a few white protrusions. Nate Berg, Curbed, "McDonald’s 2.0," 11 Apr. 2018 With their bulbous protrusions and over-the-top decorations, each dress is funnier than the one before; choreographer Laura Scozzi turns the ball choreography into a similarly hilarious, manic romp. Heidi Waleson, WSJ, "French Opera Takes Over New York," 23 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'protrusion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of protrusion

1646, in the meaning defined at sense 1

History and Etymology for protrusion

Latin protrudere

Keep scrolling for more

Learn More about protrusion

Share protrusion

Statistics for protrusion

Last Updated

23 Aug 2018

Look-up Popularity

Time Traveler for protrusion

The first known use of protrusion was in 1646

See more words from the same year

Keep scrolling for more

More Definitions for protrusion



English Language Learners Definition of protrusion

: a part that sticks out

: the act of sticking out or the condition of something that sticks out


pro·tru·sion | \prō-ˈtrü-zhən \

Medical Definition of protrusion 

1 : the quality or state of protruding the protrusion of a jaw

2 : something (as an anatomical part) that protrudes

Keep scrolling for more

Comments on protrusion

What made you want to look up protrusion? Please tell us where you read or heard it (including the quote, if possible).


evasion of direct action or statement

Get Word of the Day daily email!

Test Your Vocabulary

Great Scrabble Words—A Quiz

  • scrabble-tiles-that-read-scrabble-quiz
  • Which of the following Q-without-U words means the number five in cards or dice?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!