Green’s Dictionary of Slang

1. (US) a hip flask [? the ‘Irish’ name Michael and thus stereotype of Irish drinkers].

1914		Jackson & Hellyer Vocab. Criminal Sl. 58: michael [...] A flask of liquor. Example: ‘Have you got a michael on your hip?’.
1931		Irwin Amer. Tramp and Und. Sl. 128: Michael. – A bottle or flask carried on the hip, and hard to trace as to origin, but declared by one old-time tramp to be a reference to the fact a person proffering a drink on a cold, wet night is as welcome and as gracious as the archangel Michael.

2. (later use Aus.) the vagina [play on Michael Hunt, i.e. cunt n. (1); esp. used in joc. phr. ‘Has anyone seen Mike Hunt?’]; thus michael-muncher n., a cunnilinguist.

1731		Glass Window, or, Bog-house Miscellany B2: Here's a Health to Mich. Hunt, / And to Mich. Hunt's Breeches; / And why may not I scratch Mich. Hunt, / When Mich. Hunt itches].
1833		‘The Amiable Family’ in Fal-Lal Songster in Spedding & Watt (eds) Bawdy Songbooks (2011) III 9: He’ll nothing delight in, / Except in a writing / Of hunt on the shutters!
1835		‘Michael Hunt’ in Fanny Hill’s Bang-Up Reciter in Spedding & Watt (eds) Bawdy Songbooks (2011) III 313: Young Michael Hunt of our town he never had his like, / He was in such request his wife for shortness called him Mike; / [...] / She, missing him, went thro’ the town crying, ‘Have you seen Mike Hunt?’ .
1841		F.L.G. Swells Night Out n.p.: The dance was followed by an out-and-out song by Mike Hunt, whose name was called out in a way that must not be mentioned to ears polite].
c.1850		Peeping Tom (London) 12 48/3: [advert] Merry chaunter — Michael Hunt.
1950		‘No. 35’ Argot in G. Simes DAUS (1993).
1986		B. Hudson First Aus. Dict. Vulgarities n.p.: Michael, the formal term of address for the female genitals.
2003		McGill Reed Dict. of N.Z. Sl. 134: michael-muncher [...] a cunnilinguist. ANZ.
2006		J. O’Keeffe Red Sands 9: ‘Have you seen Mike Hunt?’ Stacey asked, smirking at all three of them. ‘What?’ said Teague. ‘Who’s he?’ ‘It ain’ta he; it’s a joke, numb-nuts.’.
2015		T. Dorsey Shark Skin Suite 211: Ask to see the driver’s license of any witness who says his name is Mike Hunt or Dick Swells.

3. (US) a ‘knockout drop’, as placed in a drink [abbr. mickey finn n.].

1952		(con. 1920s) G. Fowler Schnozzola 76: I slipped little Michael into his glass. In about five minutes little Michael took a-hold of George McManus.
1977		(con. 1940s) Hodes & Hansen Selections from the Gutter 20: She was handed a Mickey — or Michael. Now, to you who don’t know what a Michael is (and are there any who don’t?) a mickey is a pill that works wonders with a stomach [...] it makes a sissy out of a killer.