In public vehicle go to return fake (5)
I believe the answer is:
'fake' is the definition.
'in public vehicle go to return' is the wordplay.
'in' means one lot of letters goes inside another.
'public vehicle' becomes 'bus' (I've seen this before).
'to return' shows that the letters should be reversed in order.
'go' backwards is 'og'.
'bus' enclosing 'og' is 'BOGUS'.
(Other definitions for bogus that I've seen before include "Not true" , "Fake, sham" , "Fictitious" , "Pretended" , "that's not real" .)