One travelling in Cairo — American (6)
I believe the answer is:
roamer
'one travelling' is the definition.
(someone roaming around)
'in cairo american' is the wordplay.
'in' says the answer is hidden in the clue.
'ROAMER' is hidden within 'cairo american'.
(Other definitions for roamer that I've seen before include "Aimless traveller" , "One who travels aimlessly over a wide area" , "Wanderer" , "Unsettled person" .)