Reasonable, just (4)
I believe the answer is:
fair
This clue is a double definition.
'reasonable' is the first definition.
(I know that reasonable can be written as fair)
'just' is the second definition.
(just can mean fair in the sense of showing justice)
(Other definitions for fair that I've seen before include "promotional exhibition" , "Equitable ? - trade show" , "Equitable - market - not bad" , "Equitable, just (4)" , "Pretty good" .)