boundary

Noun

WordNet 3.0

Noun (3)

the line or plane indicating the limit or extent of somethingSynonyms: bound bounds
a line determining the limits of an areaSynonyms: edge bound
the greatest possible degree of something“what he did was beyond the bounds of acceptable behavior”“to the limit of his ability”Synonyms: limit bound

Webster's Dictionary (GCIDE)

Boundary \Bound"a*ry\, n.; pl. Boundaries [From Bound a limit; cf. LL. bonnarium piece of land with fixed limits.] That which indicates or fixes a limit or extent, or marks a bound, as of a territory; a bounding or separating line; a real or imaginary limit. [1913 Webster]

But still his native country lies Beyond the boundaries of the skies. --N. Cotton. [1913 Webster]

That bright and tranquil stream, the boundary of Louth and Meath. --Macaulay. [1913 Webster]

Sensation and reflection are the boundaries of our thoughts. --Locke. [1913 Webster]

Syn: Limit; bound; border; term; termination; barrier; verge; confines; precinct.

Usage: Bound, Boundary. Boundary, in its original and strictest sense, is a visible object or mark indicating a limit. Bound is the limit itself. But in ordinary usage the two words are made interchangeable. [1913 Webster]

The Devil's Dictionary

BOUNDARY, n. In political geography, an imaginary line between two nations, separating the imaginary rights of one from the imaginary rights of the other.