deado, adj. — Green’s Dictionary of Slang

deado adj.

also deadoh

[SE dead drunk + -o sfx (5)]

1. dead.

1913		J. London Valley of the Moon (1914) 23: The thing is they’re deado.
1961		T.I. Rubin In the Life 68: I’d be dead-o daddy-o if I ever told on ’em.

2. very drunk.

1933		‘William Juniper’ True Drunkard’s Delight 225: Our tippler may further be [...] dead-oh!
1937–84		Partridge DSUE (1984) 295/2: from ca. 1850.