Green’s Dictionary of Slang

1. (also hocuss) drugged liquor, thus hocuser/hokuser, one who uses such liquor to rob their victims.

1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 97: Hocus, or hocus-pocus [...] A deleterious drug mixed with wine, etc. which enfeebles the person acted upon. Horses too are hocussed, at times.
1842		Bell’s Penny Dispatch 27 Mar. 3/2: [T]he dose was too even for him for, need we say, it was a powerful hocuss, and he fell upon the ground.
1844		New Sprees of London 3: I’ll introduce you to the [...] Hokusers, Prigs, Swell-mobmen, Chanters, Actors, and all the flash and slang Mots, Donners, and Cullies that's faking the slums on the cross.
1846		Swell’s Night Guide 68: One of her mots brought home a swell well blunted, and they worked the hocus dodge on him; vell, the dose vos too multa, and the swell croaked.
1865		Leaves from Diary of Celebrated Burglar 164/1: Folkestone [...] was afraid she might ‘tumble’ to the ‘hocus’ before drinking it.

2. (US drugs) heroin, morphine or cocaine in solution, prepared for injection.

1938

D. Maurer ‘Lang. of the Und. Narcotic Addict’ Pt 2 in Lang. Und. (1981) 103/2: hocus. A ration of cocaine, morphine, or heroin in solution, ready for injection.

3. (drugs, also hokus) opium, morphine, heroin or cocaine.

1937		B. Dai Opium Addiction in Chicago 199: Hocus. Drugs in general.
1949		Monteleone Criminal Sl. (rev. edn) 120: hokus Opium.
1953		Anslinger & Tompkins Traffic In Narcotics 310: hokus. Opium.
1959		J.E. Schmidt Narcotics Lingo and Lore.
2001		ONDCP Street Terms 12: Hocus — [...] opium.

4. (drugs) marijuana.

2001

ONDCP Street Terms 12: Hocus — Marijuana.