Appropriate discussion groups outing cheat (4,3,1,4)
I believe the answer is:
take for a ride
'cheat' is the definition.
(to take someone for a ride is to cheat them)
'appropriate discussion groups outing' is the wordplay.
'appropriate' becomes 'take' (appropriate can mean to steal).
'discussion groups' becomes 'fora' (plural of forum).
'outing' becomes 'ride' (I've seen this in another clue).
'take'+'fora'+'ride'='TAKE FOR A RIDE'
(Other definitions for take for a ride that I've seen before include "Fiddle" , "Deceive - offer a lift to?" , "what elephant may do to mahout" , "Abduct to murder - cheat" , "Kid" .)