What is Bound?

Legal Definition
As an adjective, denotes the condition of bsing constrained by the obligations of a bond or a covenant. In the law of shipping, "bound to" or "bound for" denotes that the vessel spoken of is intended or designed to make a voyage to the place named. As a noun, the term denotes a limit or boundary, or a line inclosing or marking off a tract of land. In the familiar phrase "metes and bounds," the former term properly denotes the measured distances, and the latter the natural or artificial marks which indicate their beginning and ending. A distinction is sometimes taken between "bound" and "boundary," to the effect that, while the former signifies the limit itself, (and may be an imaginary line,) the latter designates a visible mark which indicates the limit. But no such distinction is commonly observed.
-- Black's Law Dictionary