Annoyed when stung? (7)
I believe the answer is:
nettled
This clue is a double definition.
'annoyed' is the first definition.
('nettle' can be a synonym of 'annoy')
'stung?' is the second definition.
('nettled' can be a synonym of 'stung')
'when' acts as a link.
(Other definitions for nettled that I've seen before include "Annoyed, irritated" , "Irritated as by stinging plant" , "Riled" , "Provoked" , "Annoyed as by stinging plant" .)