clearance

Short definition from Wiktionary

Noun

1. 1
   The act of clearing or something (such as a space) cleared.
2. 2
   The distance between two moving objects, especially between parts of a machine
3. 3
   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.
4. 4
   A permission for a vehicle to proceed, or for a person to travel.
5. 5
   A permission to have access to sensitive or secret documents or other information.
6. 6
   A permission to use something, usually intellectual property, that is legally, but not otherwise, protected.
7. 7
   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.
8. 8
   The settlement of transactions involving securities or means of payment such as checks by means of a clearing house.
9. 9
   The removal of harmful substances from the blood; renal clearance.
10. 10
    The act of potting all the remaining balls on a table at one visit.
11. 11
    The act of kicking a ball away from the goal one is defending.
12. 12
    Removal of pieces from a rank, file or diagonal so that a bishop, rook or queen is free to move along it.
13. 13
    Clear or net profit.
14. 14
    The first disposal in a chain that leaves the area of a stoppage, or a disposal that leaves the area of a stoppage itself.
15. 15
    The act of leaving the area of a stoppage.