Thus, again, makes one angry (4)
I believe the answer is:
sore
'one angry' is the definition.
(I've seen this in another clue)
'thus again' is the wordplay.
'thus' becomes 'so' (synonyms).
'again' becomes 're' (prefix meaning 'again').
'so'+'re'='SORE'
'makes' is the link.
(Other definitions for sore that I've seen before include "Spot of aggravation" , "To be very old" , "Irritated or painful" , "Hurting, painful" , "Raw or annoyed" .)