Leave to enter as a concession (9)
I believe the answer is:
admission
'concession' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for admission that I've seen before include "Anything conceded" , "yield confession of sin maybe" , "Statement acknowledging the truth of something" , "The price of entry" , "Right to go in" .)