Definition of: boundary

(boun′də·rē, -drē) noun plural ·ries
1. A limiting or dividing line or mark.
2. Any object serving to indicate a limit or confine. Synonyms: barrier, border, bound, bourn, bourne, confines, edge, enclosure, frontier, landmark, limit, line, marches, marge, margin, term, termination, verge. The boundary was originally the landmark, that which marked off one piece of territory from another. The bound is the limit, marked or unmarked. Now, however, the difference between the two words has come to be simply one of usage. As regards territory, we speak of the boundaries of a nation or of an estate; the bounds of a college, a ball ground, etc. A barrier is something that bars ingress or egress. A barrier may be a boundary, as was the Great Wall of China for many centuries. Bourn, or bourne, is a poetical expression for bound or boundary. A border is a strip, as of land, along the boundary. Edge is a sharp terminal line, as where river or ocean meets the land. Limit is now used almost wholly in the figurative sense; the limit of discussion, of time, of jurisdiction. Line is a military term: within the lines, or through the lines, of an army. Compare BARRIER, END, MARGIN.