Globetrotter's document (8)
'globetrotter's document' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for passport that I've seen before include "Traveller's ID" , "entry permit?" , "that may gain acceptance" , "This ensures admission" , "Travel authorisation" .)
(Other definitions for visa that I've seen before include "Addition to passport" , "Endorsement allowing bearer to enter country" , "travel authority" , "Mark on passport" , "Stamp affixed to passport as permission to enter country" .)