BOUNDARY

limit, bound, boundary

(noun) the greatest possible degree of something; “what he did was beyond the bounds of acceptable behavior”; “to the limit of his ability”

boundary, bound, bounds

(noun) the line or plane indicating the limit or extent of something

boundary, edge, bound

(noun) a line determining the limits of an area

Source: WordNet® 3.1

Etymology

Noun

boundary (plural boundaries)

The dividing line or location between two areas.

(cricket) An edge or line marking an edge of the playing field.

(cricket) An event whereby the ball is struck and either touches or passes over a boundary (with or without bouncing), usually resulting in an award of 4 (four) or 6 (six) runs respectively for the batting team.

(topology) (of a set) The set of points in the closure of a set $$S$$ , not belonging to the interior of that set.

Source: Wiktionary

Bound"a*ry, n.; pl. Boundaries ( Etym: [From Bound a limit; cf. LL. bonnarium piece of land with fixed limits.]

Definition: 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. But still his native country lies Beyond the boundaries of the skies. N. Cotton. That bright and tranquil stream, the boundary of Louth and Meath. Macaulay. Sensation and reflection are the boundaries of our thoughts. Locke.

Syn.

– Limit; bound; border; term; termination; barrier; verge; confines; precinct. 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.

Source: Webster’s Unabridged Dictionary 1913 Edition