Angered one on left embraced by communist (5)
I believe the answer is:
riled
'angered' is the definition.
(to rile someone up is to make them angry)
'one on left embraced by communist' is the wordplay.
'one' becomes 'i' (Roman numeral).
'on' means one lot of letters go next to another.
'left' becomes 'l' (common abbreviation).
'embraced by' indicates putting letters inside.
'communist' becomes 'red' (red can informally mean communist).
'i'+'l'='il'
'il' put into 'red' is 'RILED'.
(Other definitions for riled that I've seen before include "Nettled" , "Made angry" , "Annoyed" , "Cross" , "Irritated, provoked" .)