noun The act of clearing or something (such as a space) cleared.
noun The distance between two moving objects, especially between parts of a machine
noun The height or width of a tunnel, bridge or other passage, or the distance between a vehicle and the walls or roof of such passage; a gap, headroom.
Clearance on these freeway overpasses is limited, so big trucks must detour.
noun A permission for a vehicle to proceed, or for a person to travel.
The plane got clearance from air traffic control, and we were off.
noun A permission to have access to sensitive or secret documents or other information.
noun A permission to use something, usually intellectual property, that is legally, but not otherwise, protected.
noun A sale of merchandise, especially at significantly reduced prices, usually in order to make room for new merchandise or updated versions of the same merchandise; sometimes as a closeout.
noun The settlement of transactions involving securities or means of payment such as checks by means of a clearing house.