Unpleasant Nazi pun (5)
I believe the answer is:
nasty
'unpleasant' is the definition.
(nasty can mean unpleasant or horrible)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for nasty that I've seen before include "Evil" , "Obscene" , "rank" , "Beastly" , "Highly repugnant" .)