n.
Pronunciation: ' klir- ə n(t)s
Function: noun
Date: 1540
1 : an act or process of clearing: as a : the removal of buildings from an area (as a city slum) b : the act of clearing a ship at the customhouse also : the papers showing that a ship has cleared c : the offsetting of checks and other claims among banks through a clearinghouse d : certification as clear of objection : AUTHORIZATION <security clearance > e : a sale to clear out stock f : authorization for an aircraft to proceed especially with a specified action < clearance to land>
2 : the distance by which one object clears another or the clear space between them
3 : the volume of blood or plasma that can be freed of a specified constituent in a specified time by its excretion into the urine through the kidneys <a creatine clearance of 25 milliliters per minute> ― called also renal clearance