Always, first lady has right (4)
I believe the answer is:
ever
'always' is the definition.
(synonyms)
'first lady has right' is the wordplay.
'first lady' becomes 'eve' (I've seen this before).
'has' is a charade indicator (letters next to each other).
'right' becomes 'R' (common abbreviation).
'eve'+'r'='EVER'
(Other definitions for ever that I've seen before include "Perpetually" , "Always and permanent" , "Always, at any time" , "Eternity" , "Veer away endlessly" .)