Prudence got coarse (4)
I believe the answer is:
rude
'coarse' is the definition.
(I've seen this before)
'prudence got' is the wordplay.
'got' indicates a hidden word.
'RUDE' can be found hidden inside 'prudence'.
(Other definitions for rude that I've seen before include "discourtesy" , "Impolite or vulgar" , "Coarse or discourteous" , "Impolite or coarse" , "Impolite; basic" .)