Boundary

Noun

1. The dividing line or location between two areas.
2. The bounds, confines, or limits between immaterial things (such as one’s comfort zone, privacy, or professional sphere and the realm beyond).

   "I didn’t mean to push the boundaries by sending my boss a message on Saturday night."

3. An edge or line marking an edge of the playing field.
4. 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.

   "Travis hit a boundary to seal the match on the last ball of the over."

5. The set of points in the closure of a set S {\displaystyle S} , not belonging to the interior of that set.