Hardly a libertine (5)
I believe the answer is:
prude
'hardly a libertine' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for prude that I've seen before include "old maid" , "One easily shocked by impropriety" , "Puritan, prig" , "Priggish person" , "may be shocking for me" .)