ETYM Old Eng. bordure, French bordure, from border to border, from bord a border; of German origin; cf. Mid. High Germ. borte border, trimming, German borte trimming, ribbon; akin to Eng. board. Related to Board, Bordure.
(Homonym: border).
A strip forming the outer edge of something.

1. In programs and working environments that feature on-screen windows, the edge surrounding the user’s workspace. Window borders provide a visible frame around a document or graphic. Depending on the program and its requirements, they can also represent an area in which the cursor or a mouse pointer takes on special characteristics. For example, clicking the mouse on a window border can enable the user to resize the window or split the window in two.
2. In printing, a decorative line or pattern along one or more edges of a page or illustration.

To lie adjacent to another; SYN. adjoin, edge, abut, butt, butt against, butt on.