Pronounced single in advance (4)
I believe the answer is:
loan
'advance' is the definition.
(an advance is a loan)
'pronounced single' is the wordplay.
'pronounced' indicates a 'sounds like' (homophone) clue.
'single' becomes 'lone' (synonyms).
'lone' is a homophone of 'LOAN'.
'in' is the link.
(Other definitions for loan that I've seen before include "It's given temporarily" , "It's given but has to be returned" , "Money borrowed; lend" , "Overdraft" , "Temporary provision of money" .)