Boundary, n.; pl. Boundaries (
Etymology: [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. 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.
Shades of meaning
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. Bounds may be used for all within the limits, boundary for the limiting line only. Boundary looks to that which is without; bound only to that which is within. Hence we speak of the bounds, not the boundaries, of a subject, of the universe, etc.; we say the students were forbidden to go beyond the bounds. A barrier is something that bars ingress or egress. A barrier may be a boundary, as was the Great Wall of China. Bourn, or bourne, is a poetical expression for bound or boundary. A border is a strip 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; as, the limit of discussion, of time, of jurisdiction. Line is a military term; as, within the lines, or through the lines, of an army. Compare barrier; end.
Prepositions
The boundaries of an estate; the boundary between neighboring territories.