(2 syl.). Mr. Gifford says the Danes called their large drinking cup a rouse, and to rouse is to drink from a rouse; ca-rouse is gar-rouse, to drink all up, or to drink all —i.e. in company.
“The king doth wake to-night, and takes his rouse.”Shakespeare: Hamlet, i. 4.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894