Green’s Dictionary of Slang

1. (UK Und.) to drug a person with a mixture of a narcotic (e.g. laudanum, opium) or snuff and beer before robbing them; also of animals, e.g. race-horses.

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.
1836		‘The Whorish Jade’ in Flash Casket 58: She soon had hocussed the old cove’s eyes, / With some laudanam put in his beer; / Then grabbed all the blunt from his kicksies’ clies.
1841		‘Ax My Eye’ Dublin Comic Songster 101: Then at night am vorking burking, / Hocussing or kening svag!
1842		Whip & Satirist of NY & Brooklyn (NY) 12 Feb. n.p.: [H]ocussed by the girls [...] and then fleeced out of every farthing.
1848		Bell’s Life in Sydney 25 Nov. 2/5: He and Dicky the tailor, and Bandy Jack [...] ‘hocussed’ me down at Beatson’s public-house.
1849		Sam Sly 13 Jan. 4/2: [W]hen a gentleman was ‘hocussed’ in the establishment, ‘Doctor’ Green supplied the noxious drug.
1858		A. Mayhew Paved with Gold 252: If you’re fond of slush you may ‘suck’ it without any danger of being ‘hocussed’.
1858		Sydney Morn. Herald 13 Aug. 2/3: The days of ‘hocussing,’ ‘burking,’ ‘sticking up,’ &c, &c , have passed [...] never to return any more.
1866		Wild Boys of London I 56/2: ‘They have hocussed and robbed him, I expect,’ he said lifting the boy’s head.
1874		M. Clarke Term of His Natural Life (1897) 79: Rum? No. Eh! Laudanum! By George, he’s been hocussed!
1879		London Life 7 June 8/2: For this offence of being hocussed, Sir 'Thomas sentenced him to one month's hard labour.
1882		Sydney Sl. Dict. (2 edn) 10: My tom-tart buzzed a squatter for his skin while he was in doss. She speeled from the crib and he was turned out. I think she hocussed his lush / My girl robbed a squatter of his purse while he was asleep. She left the house and he was turned out. I think she drugged his liquor.
1888		W.B. Churchward Blackbirding In The South Pacific 18: I can feel my bursting head, from the hocussing I had gone through. [Ibid.] 43: They had been hocussed in grog shanties on shore, kidnapped and sold to the ship, just as I had been at Liverpool.
1892		H. Nisbet Bushranger’s Sweetheart 108: We had to hocus their drink.
1904		‘Dryblower’ ‘Thy Will Be Done’ in Sun. Times (Perth) 3 Jan. 12/1: The old dryblower who said he was hocussed and robbed of his ‘shammy’.
1905		E.W. Hornung A Thief in the Night (1992) 382: My trap for crooks and cracksmen is a bottle of hocussed whiskey.
1909		J. Ware Passing Eng. of the Victorian Era 115/2: Doping (Racing, 1900). Hocussing rather than poisoning racehorses when about to run.
1922		E. Dyson Missing Link 🌐 Ch. xvi: The Missing Link took a good, long pull, and in less than half a minute was [...] dead to the world, a thoroughly hocussed man-monkey.
1934		O. Strange Sudden 12: The liquor he was invited to sample might be hocussed.
1940		O. Strange Sudden Takes the Trail 153: Hocussed liquor makes their job easy.
1999		G. Seal Lingo 133: The problems associated with over-proof and downright dangerous concoctions are also numerous in colloquial speech: [...] hocussed (drugged) grog; blow-me-skull-off; the offensive gin’s piss.

2. in general use, to adulterate.

1852

G.C. Mundy Our Antipodes I 232: ‘Damper’ well ‘hocussed’ with arsenic or strychnine, was laid in the way of the savages.