Go sightseeing (4)
I believe the answer is:
tour
'go sightseeing' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tour that I've seen before include "A trip round" , "'Pleasure journey, visiting various places (4)'" , "Trip visiting several places" , "Journey visiting several different places" , "Term of duty" .)