Emphasise account needs money (6)
I believe the answer is:
accent
'emphasise' is the definition.
(synonyms)
'account needs money' is the wordplay.
'account' becomes 'ac' (abbreviation for account).
'needs' means one lot of letters go next to another.
'money' becomes 'cent' (eg denomination of dollars).
'ac'+'cent'='ACCENT'
(Other definitions for accent that I've seen before include "Particular emphasis" , "Regional speech characteristic" , "Mark to modify letter" , "Distinctive way fo speaking" , "intensity" .)