Leaving some Tango in glass (5)
I believe the answer is:
going
'leaving' is the definition.
(I know that leaving can be written as going)
'some tango in glass' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'GOING' is hidden within 'tango in glass'.
(Other definitions for going that I've seen before include "State of ground (racing)" , "State of turf" , "Failing to stay" , "Moving away, departing" , "Ground condition for horse racing" .)