Worked up in choir at Exeter (5)
I believe the answer is:
irate
'worked up' is the definition.
(thesaurus)
'in choir at exeter' is the wordplay.
'in' indicates a hidden word.
'IRATE' can be found hidden inside 'choir at exeter'.
(Other definitions for irate that I've seen before include "Spitting feathers" , "Livid" , "Annoyed, nettled" , "Cross, irritated" , "Aggrieved" .)