spit and a drag, n. — Green’s Dictionary of Slang

spit and a drag n.

[? rhy. sl. = fag n.³ (2), or the result of a badly rolled cigarette, from which one spits out the odd strand of tobacco, while dragging or drawing down the smoke]

a cigarette.

1938		J. Curtis They Drive by Night 283: Let a bloke have a spit and a drag I shouldn’t wonder.
1943		R. Llewellyn None But the Lonely Heart 100: Want a spit and a drag, chum?
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.