protrude

Protrude is a verb meaning to extend beyond the surface or to stick out beyond an enclosing boundary. It describes something that projects, juts, or becomes visible because it extends past surrounding material or space. The verb can be used for physical objects as well as for parts of the body or other elements that break the plane of a surface.

Etymology traces protrude to the Latin protrudere, from pro- “forward” and trudere “to thrust.” The related noun protrusion refers to the act or instance of protruding. The adjective forms include protruding and protrusive, indicating something that tends to extend outward or that causes a projection.

Usage across contexts varies. In everyday language, one can say a rock protrudes from a cliff, a bone protrudes under the skin, or a person’s chin protrudes. In dentistry and orthopedics, protrusion often describes forward-positioned teeth or bones, such as dental protrusion or a protruding jaw. In spinal medicine, disc protrusion denotes bulging disc material that extends beyond the disc’s normal boundary but remains attached, whereas extrusion implies that material has broken through the outer layer and may separate from the disc.

Protrude is typically intransitive, used with prepositions such as from, beyond, or out of, though it can be described as causing a protrusion or protrusive shape in a broader sense. Common synonyms include jut, project, and bulge, while related terms include protruding, protrusive, and protrusion.