Tricked about party — that's forgiven (8)
I believe the answer is:
condoned
'forgiven' is the definition.
(condoning is a kind of forgiving)
'tricked about party' is the wordplay.
'tricked' becomes 'conned' (I've seen this before).
'about' is an insertion indicator.
'party' becomes 'do' (do is a kind of party).
'conned' enclosing 'do' is 'CONDONED'.
'that's' acts as a link.
(Other definitions for condoned that I've seen before include "Sanctioned" , "Excused, overlooked" .)