Fraudulent coach holding game up (5)
I believe the answer is:
bogus
'fraudulent' is the definition.
(thesaurus)
'coach holding game up' is the wordplay.
'coach' becomes 'bus' ('bus' can be a synonym of 'coach'**).
'holding' is an insertion indicator.
'game' becomes 'go' (go is a kind of game).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'go' back-to-front is 'og'.
'bus' placed around 'og' is 'BOGUS'.
(Other definitions for bogus that I've seen before include "taking one for a ride?" , "Sham, counterfeit" , "Phoney, not genuine" , "Sham, false" , "Fictitious" .)