boundary

n. limit, border

Boundary (plural: boundaries) may refer to:A border that encloses a space or an abstract conceptBoundary in surveying is the dividing line between parcels of land, and the subject of a 'boundary survey'Boundary (cricket), the border of the field in the sport of cricketBoundary (topology), the set of points in the closure of a subset of a topological space'Boundary', an edge in the topology of manifolds, as in the case of a 'manifold with boundary'Boundary (thermodynamic), the edge of a thermodynamic system across which heat, mass, or work can flowBoundary (Sword of Truth), a fictional location in the fantasy series by Terry GoodkindBoundaries in landscape history, the divide between areas of differing land useBoundaries (film), a 1997 movie starring Playboy 'playmate' Kathy Shower
See more at Wikipedia.org...

Noun
1. the line or plane indicating the limit or extent of something
(synonym) bound, bounds
(hypernym) extremity
(hyponym) hairline
(derivation) bound, border
2. a line determining the limits of an area
(synonym) edge, bound
(hypernym) line
(hyponym) rim
(derivation) bound, border
3. the greatest possible degree of something; "what he did was beyond the bounds of acceptable behavior"; "to the limit of his ability"
(synonym) limit, bounds
(hypernym) extent
(hyponym) knife-edge

(n.)
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.
  

1. the dividing point between two performance sectors.
2. the border around a market area that is being studied.