Beer container, almost dry, left (6)
I believe the answer is:
barrel
'beer container' is the definition.
(I've seen this before)
'almost dry left' is the wordplay.
'almost dry' becomes 'barre' (I can't justify this - if you can you should believe this answer much more).
'left' becomes 'l' (common abbreviation).
'barre'+'l'='BARREL'
Can you help me to learn more?
(Other definitions for barrel that I've seen before include "Measure of oil" , "Beer measure; gun part" , "Oil or beer container" , "full of laughs?" , "Round wooden vessel." .)