Traveller briefly repelled girl viewer (8)
I believe the answer is:
spyglass
'viewer' is the definition.
(I've seen this before)
'traveller briefly repelled girl' is the wordplay.
'traveller' becomes 'gypsy' (gypsy is a kind of traveller).
'briefly' means to remove the last letter.
'repelled' says the letters should be written backwards.
'girl' becomes 'lass' (lass is a kind of girl**).
'gypsy' with its final letter taken away is 'gyps'.
'gyps' backwards is 'spyg'.
'spyg'+'lass'='SPYGLASS'
(Other definitions for spyglass that I've seen before include "little scope" , "Viewing aid" , "See-through article" , "that magnifies" , "Aid to pirate, perhaps" .)