Inclination of Eastender having a complaint (3)
I believe the answer is:
ill
'having a complaint' is the definition.
(unwell with a medical complaint)
I can't explain the remainder of the clue.
(Other definitions for ill that I've seen before include "Unwell from bacillus" , "Out of sorts" , "Infirm" , "Groggy" , "Imperfectly; unwell" .)