Party with peanuts provided regularly for Will, maybe? (8)
I believe the answer is:
document
'will maybe?' is the definition.
(a will is a type of legal document)
'party with peanuts provided regularly' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'with' becomes 'cum' ('with' in Latin).
'provided regularly' indicates alternate letters (letters taken at regular intervals).
The alternate letters of 'peanuts' are 'ent'.
'do'+'cum'+'ent'='DOCUMENT'
'for' is the link.
(Other definitions for document that I've seen before include "Will, for example" , "Evidence" , "Written record" , "Paper, form" , "Written statement" .)