Sit angrily suffering sore throat (10)
I believe the answer is:
laryngitis
'sore throat' is the definition.
(I've seen this before)
'sit angrily suffering' is the wordplay.
'suffering' indicates an anagram.
'sit'+'angrily'='sitangrily'
'sitangrily' is an anagram of 'LARYNGITIS'.
(Other definitions for laryngitis that I've seen before include "Inflammation of the windpipe" , "Sore throat" , "Inflammation of the vocal cords" , "Throat infection" , "Inflammation of part of throat" .)