clearance

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

See clearance defined for English-language learners

See clearance defined for kids

First Known Use of CLEARANCE

1540

Related to CLEARANCE

Synonyms: allowance, authorization, permission, concurrence, consent, granting, green light, leave, license (or licence), sanction, sufferance, warrant

Antonyms: interdiction, prohibition, proscription

Other Aeronautics/Aerospace Terms

airway, apron, corridor, dirigible, fishtail, flat-hat, vector

CLEARANCE Defined for Kids

clearance

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

clearance

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