Traveller needing fresh air in tent (9)
I believe the answer is:
itinerant
'traveller' is the definition.
(itinerant is a kind of traveller)
'fresh air in tent' is the wordplay.
'fresh' is an anagram indicator.
'air'+'in'+'tent'='airintent'
'airintent' is an anagram of 'ITINERANT'.
'needing' acts as a link.
(Other definitions for itinerant that I've seen before include "Rambling" , "Moving from place to place" , "Wandering from place to place" , "Person who moves from place to place" , "Travelling around" .)