Slowly advanced, with love (5)
I believe the answer is:
lento
'slowly' is the definition.
('lento' can be a synonym of 'slowly')
'advanced with love' is the wordplay.
'advanced' becomes 'lent' (money).
'with' is a charade indicator (letters next to each other).
'love' becomes 'o' (In tennis, 'love' means 'zero').
'lent'+'o'='LENTO'
(Other definitions for lento that I've seen before include "Musically low speed" , "Old sayings" , "Slow (music)" , "Instruction to players" , "It's slower than adagio" .)