Prude (4)
I believe the answer is:
prig
'prude' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for prig that I've seen before include "Snooty type?" , "Smug type" , "Old maid" , "Self-righteous moralist" , "Unpleasant arrogant person" .)