Psychic in fair (6)
I believe the answer is:
medium
I believe this is a double definition.
'psychic' is the first definition.
(medium is a kind of psychic)
'fair' is the second definition.
(thesaurus)
'in' is the link.
(Other definitions for medium that I've seen before include "Average - means of communication" , "Intermediary with the spirit world" , "Average or intermediate" , "Spiritualist who conducts seances" , "Average, middling" .)