To trade in answer not in fact fair, somehow (7)
I believe the answer is:
traffic
'to trade in' is the definition.
(thesaurus)
'answer not in fact fair somehow' is the wordplay.
'answer' becomes 'a' (abbreviation eg in Q and A).
'not in' is a deletion indicator.
'somehow' indicates anagramming the letters.
'fact'+'fair'='factfair'
'factfair' with 'a' taken away is 'fctfair'.
'fctfair' is an anagram of 'TRAFFIC'.
(Other definitions for traffic that I've seen before include "Group" , "Trade (in cars?)" , "Movement of vehicles" , "dealings" , "Passing vehicles - trade" .)