n.1 the removal of obstructions etc., esp. removal of buildings, persons, etc., so as to clear land.
2 clear space allowed for the passing of two objects or two parts in machinery etc.
3 special authorization or permission (esp. for an aircraft to take off or land, or for access to information etc.).
4 a the clearing of a person, ship, etc., by customs. b a certificate showing this.
5 the clearing of cheques.
6 Football a kick sending the ball out of a defensive zone.
7 making clear.
Phrases and idioms:
clearance order an order for the demolition of buildings. clearance sale Brit. a sale to get rid of superfluous stock.