Drink in one club, being entertained by hero (8)
I believe the answer is:
libation
'drink' is the definition.
(libation is a kind of drink)
'one club being entertained by hero' is the wordplay.
'one' becomes 'i' (Roman numeral).
'club' becomes 'bat' (I've seen this before).
'being entertained by' is an insertion indicator (I've seen this in other clues).
'hero' becomes 'lion'.
'i'+'bat'='ibat'
'ibat' placed inside 'lion' is 'LIBATION'.
'in' is the link.
(Other definitions for libation that I've seen before include "Ritual of pouring wine as sacrifice to a god" , "A serving of an alcoholic beverage" , "Drink poured out as offering to God" , "Drink poured as offering to the gods" , "Liquid offering" .)