1 [uncountable and countable]
the process of getting official permission or approval for something:
She'll race if she gets medical clearance from her doctor.
Morris did not have a security clearance.
2 [uncountable and countable]
official permission for a plane to take off or land
The pilot requested clearance for an emergency landing.
3 [uncountable and countable]
the removal of unwanted things from a place:
the clearance of minefields
snow/land/slum etc clearance
flooding caused by forest clearance
4 [uncountable and countable]
the amount of space around one object that is needed for it to avoid touching another object:
There was less than a foot's clearance between the ship's sides and the wharf.
5 [uncountable and countable]BFB
a process by which a cheque goes from one bank to another
an occasion when a player in a game such as football kicks the ball away from his or her goal