protrusion

noun

pro·​tru·​sion prō-ˈtrü-zhən 

1

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

2

: the act of protruding : the state of being protruded

Synonyms

• projection
• protuberance
• bulge
• section
• dome
• overhang
• convexity
• portion
• swell

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.

Recent Examples on the Web

As per the press release, these included small, circular protrusions or bumps, elliptical protrusions with a fingerprint-like pattern, and a third set of large, round marks. —Mrigakshi Dixit, Interesting Engineering, 8 Sep. 2025

Their name comes from the unique protrusions on their back that resemble horns and serve as a defense mechanism against predators including other sharks, elephant seals and some large fish. —Ashley MacKin Solomon, San Diego Union-Tribune, 7 Sep. 2025

They are covered in small protrusions, reminiscent of warts. —Irene Wright, Miami Herald, 22 Aug. 2025

Improper footwear may cause or exacerbate bunions, protrusions of the big toe knuckles. —Lauren Leffer, Popular Science, 20 Aug. 2025

Word History

Etymology

Latin protrudere

First Known Use

1646, in the meaning defined at sense 2

Rhymes for protrusion

• allusion
• collusion
• conclusion
• confusion
• contusion
• delusion
• diffusion
• effusion
• exclusion
• extrusion
• illusion
• inclusion

Kids Definition

protrusion

noun

pro·​tru·​sion prō-ˈtrü-zhən 

1

: the act of protruding : the state of being protruded

2

: something that protrudes

Medical Definition

protrusion

noun

pro·​tru·​sion prō-ˈtrü-zhən 

1

: the quality or state of protruding

the protrusion of a jaw

2

: something (as an anatomical part) that protrudes