Blonde female character (4)
I believe the answer is:
fair
'blonde' is the definition.
(similar in meaning)
'female character' is the wordplay.
'female' becomes 'f' (abbreviation).
'character' becomes 'air' (air can mean a character or mood).
'f'+'air'='FAIR'
(Other definitions for fair that I've seen before include "Just treatment of others" , "Equitable ? - trade show" , "Just; beautiful; blond" , "Reasonable target?" , "'Just, meet (4)'" .)