Just a trade show (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)
'a trade show' is the second definition.
(I've seen this before)
(Other definitions for fair that I've seen before include "Just; gala" , "Traders' gathering" , "Just - swings and roundabouts" , "Moderately good; blonde" , "honest" .)