He claims that he was 'stone cold sober' [=completely sober] when the accident happened.
She has been 'sober' for three years. [=she stopped drinking alcohol three years ago]
I haven't been drinking at all. I'm '(as) sober as a judge'. [=I'm completely sober]
(..) But he's a loser! He's pathetic! He's-- A Simpson. Hmm. Maybe I should call the police. - Oh, he'll sober up. - Yeah. Come staggering home. Mm-hmm. Smelling of cheap perfume. - Homer! - What? What the-- Who the-- (..)1989 TvShow: The Simpsons Title: Simpsons Roasting on an Open Fire Season: 1 Episode 1