out of (one's) box(redirected from out of his box)
out of (one's) box
slang Very intoxicated from drugs or alcohol. Primarily heard in UK. You were really out of your box last night! How do you feel this morning? A: "Do you remember anything you said to me at the party?" "B: "Not at all—I was out of my box last night."
out of your boxBRITISH, INFORMAL
If someone is out of their box, they are drunk or affected by drugs, or are very foolish. The guy must have been seriously out of his box! Note: In this expression, `box' refers to someone's head. Compare with out of your head.