Mid-channel? (6)
I believe the answer is:
medium
This clue is a double definition.
'mid' is the first definition.
(thesaurus)
'channel?' is the second definition.
(I've seen this before)
(Other definitions for medium that I've seen before include "Average; agency" , "Person who conducts a siance" , "The middle between two extremes" , "Average - means of communication" , "Intermediary with the spirit world" .)