Empty the bottle. A corruption of bouse (to drink).
In bousing a bout `twas his gift to excel And of all jolly topers he bore off the bell.
(A). A rumour, a whispered report.
Yes, that, on every dream, Each buzz, each fancy ... He may enguard his dotage.
Shakespeare: King Lear, i. 4.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894