One powerful star mostly supported by a woman's love (9)
I believe the answer is:
superhero
'one powerful star' is the definition.
The definition suggests a singular noun which matches the answer.
'mostly supported by a woman's love' is the wordplay.
'mostly' becomes 'super' (I can't explain this - if you can you should give a lot more credence to this answer).
'supported by' is a charade indicator (letters next to each other) (in a down clue, some letters hold up others).
'a woman's' becomes 'her' (belonging to a woman).
'love' becomes 'o' (love means zero in tennis).
'super'+'her'+'o'='SUPERHERO'
Can you help me to learn more?
(Other definitions for superhero that I've seen before include "people didn't notice in Kent, for one" , "Fictional character with special powers" , "Her poseur (anag.)" , "Fantastic character" , "Spiderman, for example" .)