After drink, get hold of boxed item (8)
I believe the answer is:
punchbag
'hold of boxed item' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'after drink get' is the wordplay.
'after' means one lot of letters go next to another.
'drink' becomes 'punch' (punch is an alcoholic drink).
'get' becomes 'bag' (bag can mean to secure or obtain).
'punch' next to 'bag' is 'PUNCHBAG'.
Can you help me to learn more?
(Other definitions for punchbag that I've seen before include "Someone continually attacked" , "victim of much aggression" .)