Sit angrily, disposed to make a complaint (10)
I believe the answer is:
laryngitis
'a complaint' is the definition.
(laryngitis is a kind of disease)
'sit angrily disposed' is the wordplay.
'disposed' indicates anagramming the letters.
'sit'+'angrily'='sitangrily'
'sitangrily' is an anagram of 'LARYNGITIS'.
'to make' is the link.
(Other definitions for laryngitis that I've seen before include "Inflammation making it difficult to speak" , "Inflammation of part of throat" , "Throat infection" , "Inflammation of the vocal cords" , "Inflammation of the windpipe" .)