Be nice to a woman who's without a man, for love (3)
I believe the answer is:
woo
'be nice to a woman' is the definition.
I can't tell whether this definition defines the answer.
'without a man for love' is the wordplay.
I cannot quite understand how this works, but
'without' could be 'wo' (abbreviation of 'without', normally with a slash) and 'wo' is present in the answer.
'love' could be 'o' (love means zero in tennis) and 'o' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'who's' acts as a link.
Can you help me to learn more?
(Other definitions for woo that I've seen before include "Pay court to" , "Do courting" , "Court a lady" , "Court (someone)" , "Try to get the girl?" .)