Cadge a drink then beat it! (6)
I believe the answer is:
begone
'beat it' is the definition.
(thesaurus)
'cadge a' is the wordplay.
'cadge' becomes 'beg' (I've seen this before).
'a' becomes 'one'.
'beg'+'one'='BEGONE'
'drink then' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for begone that I've seen before include "shove off" , "Take a hike" , "make himself scarce" , "Archaic word of dismissal" , "get lost" .)