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noun clear·ance \ˈklir-ən(t)s\

: an official decision saying that someone has permission to do something

: official permission for an aircraft, pilot, etc., to do something

: the amount of space between two things

Full Definition of CLEARANCE

:  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>
:  the distance by which one object clears another or the clear space between them
:  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

Examples of CLEARANCE

  1. She has a security clearance that allows her to see the classified information.
  2. The pilot got clearance to land.
  3. That flight has not received clearance for landing.
  4. There was only 10 inches of clearance between the car and the side of the tunnel.
  5. a bridge with a 100-foot clearance above the water
  6. the clearance of forests for farming
  7. slum clearance to make room for new housing

First Known Use of CLEARANCE


Other Aeronautics/Aerospace Terms

airway, apron, corridor, dirigible, fishtail, flat-hat, vector
CLEARANCE Defined for Kids


noun clear·ance \ˈklir-əns\

Definition of CLEARANCE for Kids

:  the act or process of removing something
:  the distance by which one object avoids hitting or touching another
:  official permission <The plane has clearance to land.>
Medical Dictionary


noun clear·ance \ˈklir-ən(t)s\

Medical Definition of CLEARANCE

:  the volume of blood or plasma that could be freed of a specified constituent in a specified time (usually one minute) by excretion of the constituent into the urine through the kidneys—called also renal clearance


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