A waste of time with empty beer glass, nothing to drink (9)
I believe the answer is:
pointless
'a waste of time' is the definition.
(something pointless is a waste of time)
'with empty beer glass nothing to drink' is the wordplay.
'with empty beer glass' becomes 'pintless' (without a pint).
'nothing' becomes 'O' (looks like zero - 0).
'to drink' indicates putting letters inside (some letters drink up others).
'pintless' going around 'o' is 'POINTLESS'.
(Other definitions for pointless that I've seen before include "unprofitable" , "Futile - TV quiz show" , "Single-track railway might be so" , "Futile - blunt" , "absurd" .)