Overlook number holding endless wild party (7)
I believe the answer is:
forgive
'overlook' is the definition.
(thesaurus)
'number holding endless wild party' is the wordplay.
'number' becomes 'five' (five is a kind of number**).
'holding' is an insertion indicator.
'endless' means to remove the last letter.
'wild party' becomes 'orgy' (I've seen this before).
'orgy' with its final letter removed is 'org'.
'five' enclosing 'org' is 'FORGIVE'.
(Other definitions for forgive that I've seen before include "Condone" , "Pardon" , "Absolve" , "free of blame" , "Excuse (an offence)" .)