Pure; restrained (6)
I believe the answer is:
chaste
I believe this clue is a double definition.
'pure' is the first definition.
(chaste means abstaining from sex)
'restrained' is the second definition.
(chaste can mean restrained or simple)
(Other definitions for chaste that I've seen before include "'Celibate, virginal (6)'" , "Decorous" , "Morally pure" , "avoiding relations" , "not spotted at all" .)