Annoying expats I anger anew (12)
I believe the answer is:
exasperating
'annoying' is the definition.
(synonyms)
'expats i anger anew' is the wordplay.
'anew' is an anagram indicator.
'expats'+'i'+'anger'='expatsianger'
'expatsianger' anagrammed gives 'EXASPERATING'.
(Other definitions for exasperating that I've seen before include "Irksome" , "Very frustrating" , "Infuriating" , "Extremely annoying" .)