Always in same version (4)
I believe the answer is:
ever
'always' is the definition.
(synonyms)
'in same version' is the wordplay.
'in' indicates a hidden word.
'EVER' is hidden within 'same version'.
(Other definitions for ever that I've seen before include "To the end of time" , "At all times, always" , "Always and permanent" , "constantly" , "Perpetually" .)