Prudence gets discourteous (4)
I believe the answer is:
rude
'discourteous' is the definition.
(thesaurus)
'prudence gets' is the wordplay.
'gets' says the answer is hidden in the clue.
'RUDE' is hidden in the letters of 'prudence'.
(Other definitions for rude that I've seen before include "having no manners?" , "Impolite; unpolished" , "Offensively impolite" , "Offensive; unpolished" , "lacking refinement" .)