Note parking concession (3)
I believe the answer is:
sop
'concession' is the definition.
(I know that sop is a type of concession)
'note parking' is the wordplay.
'note' becomes 'so' (musical note).
'parking' becomes 'p' (abbreviation on road signs).
'so'+'p'='SOP'
(Other definitions for sop that I've seen before include "A concession or bribe, once offered to Cerberus" , "Small concession" , "Appeasing gift" , "Piece of bread dipped in liquid, or a concession" , "Bread dipped in gravy" .)