A woman's right, always! (4)
I believe the answer is:
ever
'always' is the definition.
(synonyms)
'a woman's right' is the wordplay.
'a woman' becomes 'eve' (Eve is an example).
'right' becomes 'r' (common abbreviation).
'eve'+'r'='EVER'
(Other definitions for ever that I've seen before include "Always and permanent" , "In perpetuity" , "At all times, always" , "To the end of time" , "Continuously" .)