in one's cups

in (one's) cups

Inebriated with alcohol. When you're in your cups, foolish ideas have a peculiar tendency of sounding like excellent ones. He called to apologize the following morning, claiming that he had been in his cups when he made those rude remarks.
See also: cup

in one's cups

Drunk, as in You can't believe anything he says when he's in his cups. [Early 1600s]
See also: cup