protrusion

/proʊˈtruʒən/

/prəʊˈtruʒən/

Other forms: protrusions

Anything that sticks or juts out from a surface is a protrusion. When you're rock climbing, every protrusion is a possible handle to grab or step to stand on.

In medicine, most protrusions are evidence of some disorder or illness, like a bulging protrusion in your belly. Most other protrusions, though, are perfectly normal: your nose is a protrusion in the middle of your face, and a spire can be described as a protrusion on the top of a church. The Latin source of protrusion is protrudere, "to push out."

Definitions of protrusion

1. noun

   something that bulges out or is protuberant or projects from its surroundings
   synonyms: bulge, bump, excrescence, extrusion, gibbosity, gibbousness, hump, jut, prominence, protuberance, swelling

   types:

   frontal eminence

   either prominence of the frontal bone above each orbit

   occipital protuberance

   prominence on the outer surface of the occipital bone

   belly

   a part that bulges deeply

   caput

   a headlike protuberance on an organ or structure

   mogul

   a bump on a ski slope

   nub, nubble

   a small lump or protuberance

   snag

   a sharp protuberance

   wart

   any small rounded protuberance (as on certain plants or animals)

   type of:

   projection

   any solid convex shape that juts out from something
2. noun

   the act of projecting out from something
   synonyms: jut, jutting, projection

   type of:

   change of shape

   an action that changes the shape of something