Returning to add, it is an ear inflammation (6)
I believe the answer is:
otitis
'an ear inflammation' is the definition.
(I've seen this before)
'returning to add it is' is the wordplay.
'returning' says the letters should be written in reverse.
'add' says to put letters next to each other.
'to' reversed gives 'ot'.
'ot'+'it'+'is'='OTITIS'
(Other definitions for otitis that I've seen before include "complaint?" , "Condition of shell-like" , "Inflammation of the ear" , "trouble with hearing device" , "problem for listener" .)