verb To divide an angle, line segment, or other figure into two equal parts.
verb To perform a binary search on files in source control in order to identify the specific change that introduced a bug etc.
noun A bisector, which divides into two equal parts.
noun An envelope, card, or fragment thereof showing an affixed cut half of a regular issued stamp, over which one or more postal markings have been applied. Typically used in wartime when normal lower rate stamps may not be available.