Returning short gypsy girl's telescope (8)
I believe the answer is:
spyglass
'telescope' is the definition.
(spyglass is a kind of telescope)
'returning short gypsy girl's' is the wordplay.
'returning' says the letters should be written backwards.
'short' means to remove the last letter.
'girl' becomes 'lass' (lass is a kind of girl**).
'gypsy' with its final letter removed is 'gyps'.
'gyps' back-to-front is 'spyg'.
'spyg'+'lass'='SPYGLASS'
(Other definitions for spyglass that I've seen before include "little scope" , "that magnifies" , "Aid to pirate, perhaps" , "Viewing aid" , "See-through article" .)