Green’s Dictionary of Slang

miller’s point n.

(N.Z. prison) .

1982		G. Newbold Big Huey 251: Millers point (n) Marijuana cigarette.
1994		B. Payne Poor Behaviour 81: He produces a marijuana cigarette. ‘I got a big fat millers here, Dee. Me last one’.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 116/2: millers point (also miller) n. a cigarette containing marijuana.