Contracted, which irritated one (3)
I believe the answer is:
got
This might be a double definition.
'contracted' is the first definition.
('get' can be a synonym of 'contract')
'irritated one' is the second definition.
'got' can be an answer for 'irritated' (I've seen this in other clues). I'm not sure about the 'one' bit.
'which' acts as a link.
Can you help me to learn more?
(Other definitions for got that I've seen before include "Received; understood" , "Landed" , "Acquired" , "came by" , "Caught" .)