Norma's terrible Italian (5)
I believe the answer is:
roman
'italian' is the definition.
(someone from Rome)
'norma's terrible' is the wordplay.
'terrible' indicates an anagram.
'norma' with letters rearranged gives 'ROMAN'.
(Other definitions for roman that I've seen before include "Of an Italian city" , "Type of candle, nose etc" , "(Of a nose) high-bridged" , "eg Julius Caesar" , "Like a type" .)