Notice embassy's entrance (9)
I believe the answer is:
admission
'entrance' is the definition.
(admission is a kind of entrance)
'notice embassy's' is the wordplay.
'notice' becomes 'ad'.
'embassy' becomes 'mission' (I've seen this before).
'ad'+'mission'='ADMISSION'
(Other definitions for admission that I've seen before include "for which one may be charged" , "yield confession of sin maybe" , "Access" , "guilt?" , "Ticket holders expect this" .)