Girl right at all times (4)
I believe the answer is:
ever
'at all times' is the definition.
(synonyms)
'girl right' is the wordplay.
'girl' becomes 'eve' ().
'right' becomes 'r' (abbreviation).
'eve'+'r'='EVER'
(Other definitions for ever that I've seen before include "Perpetually" , "At all times, always" , "Possibly" , "Eternity" , "On any occasion" .)