The meaning of BOUNDARY is something that indicates or fixes a limit or extent. How to use boundary in a sentence.

BOUNDARY definition: a line or limit where one thing ends and another begins, or something that indicates such a line or limit. See examples of boundary used in a sentence.

BOUNDARY definition: 1. a real or imagined line that marks the edge or limit of something: 2. the limit of a subject or…. Learn more.

The boundary of an area of land is an imaginary line that separates it from other areas.

something that indicates bounds or limits, as a line: A mountain range forms a natural boundary between the two countries.

boundary A line that delineates surface areas for the purpose of facilitating coordination and deconfliction of operations between adjacent units, formations, or areas.

Mar 21, 2026 · Noun boundary (plural boundaries) The dividing line or location between two areas.

In the pre-modern world, the term border was vague and could refer to either side of the boundary, thus it was necessary to specify part of it with borderline or borderland. During the medieval period the …

A boundary refers to a line, point or plane that marks the limit or edge of something or separates one thing from another such as concepts, objects, territories, or phenomena.

Those two trees mark the boundary of our property. The river forms the country's western boundary.