Annoyed, having gone ahead after demand (7)
I believe the answer is:
needled
'annoyed' is the definition.
(needle can mean to annoy or irritate)
'gone ahead after demand' is the wordplay.
'gone ahead' becomes 'led' ('lead' can be a synonym of 'go'. I am not sure about the 'ahead' bit.).
'after' means one lot of letters go next to another.
'demand' becomes 'need' (synonyms).
'led' after 'need' is 'NEEDLED'.
'having' is the link.
Can you help me to learn more?
(Other definitions for needled that I've seen before include "Goaded or provoked" , "was annoying" , "Annoyed - provoked" , "Provoked with sewing implement" , "Piqued" .)