Channel taking middle course (6)
I believe the answer is:
medium
I believe this is a double definition.
'channel' is the first definition.
(thesaurus)
'middle course' is the second definition.
(thesaurus)
'taking' acts as a link.
(Other definitions for medium that I've seen before include "Spiritualist in charge of seance" , "The middle between two extremes" , "Spiritualist who conducts seances" , "Average or intermediate" , "Neither big nor small" .)