Commuter's ticket -- green, possibly (9)
I believe the answer is:
passenger
'commuter's' is the definition.
(thesaurus)
'ticket green possibly' is the wordplay.
'ticket' becomes 'pass' (pass is a kind of ticket).
'possibly' is an anagram indicator.
'green' is an anagram of 'enger'.
'pass'+'enger'='PASSENGER'
(Other definitions for passenger that I've seen before include "One on team doing little effective work" , "One's driven" , "Person being carried in another's vehicle" , "One driven" , "One on a train perhaps" .)