Wound up line that has caught on the outside (7)
I believe the answer is:
nettled
'wound up' is the definition.
(nettle can mean to irritate)
'line that has caught on the outside' is the wordplay.
I cannot quite understand how this works, but
'line' could be 'l' and 'l' is found in the answer.
'caught' could be 'netted' (netting is a kind of catching) and 'netted' is found in the remaining letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
(Other definitions for nettled that I've seen before include "Provoked" , "Riled" , "becomes annoyed" , "annoyed one" , "Annoyed as by stinging plant" .)