Salesman has teacher returning as a traveller (7)
I believe the answer is:
tourist
'a traveller' is the definition.
(I know that tourist is a type of traveller)
'salesman has teacher returning' is the wordplay.
'salesman' becomes 'tout' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'has' is an insertion indicator.
'teacher' becomes 'sir' (way of addressing a male teacher).
'returning' shows that the letters should be reversed in order.
'sir' written backwards gives 'ris'.
'tout' enclosing 'ris' is 'TOURIST'.
'as' acts as a link.
Can you help me to learn more?
(Other definitions for tourist that I've seen before include "Sightseeing traveller" , "someone on holiday" , "Someone who travels for pleasure" , "Cheap travel class" , "Person travelling for pleasure" .)