Drunk nearly crosses border, creating rumpus (9)
I believe the answer is:
shemozzle
'rumpus' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'drunk nearly crosses border' is the wordplay.
'drunk nearly' becomes 'sozzle' (I can't justify this - if you can you should give a lot more credence to this answer).
'crosses' is an insertion indicator.
'border' becomes 'hem' (I've seen this before).
'sozzle' enclosing 'hem' is 'SHEMOZZLE'.
'creating' is the link.
Can you help me to learn more?
(Other definitions for shemozzle that I've seen before include "Confused situation or affair, a mess" , "Commotion" , "muddle" , "Confused state" , "Noisy confusion - uproar" .)