Just, impartial (4)
I believe the answer is:
fair
I believe this clue is a double definition.
'just' is the first definition.
(just can mean fair in the sense of showing justice)
'impartial' is the second definition.
(associated in meaning)
(Other definitions for fair that I've seen before include "nothing special" , "likely" , "Average" , "Attractive type of weather?" , "Travelling show is impartial" .)