Green’s Dictionary of Slang

1. to boast; to talk nonsense; to speak criminal cant.

1937–84

Partridge DSUE (1984) 1092/2: ca. 1820–80.

2. (UK Und.) to pass off counterfeit money.

1847		G.M.W. Reynolds Mysteries of London III 66/1: Tim sent the yack to church and christen but the churchman came to it through poll, as Tim’s shaler had slummed on him a sprat and an alderman last week.
1882		Sydney Sl. Dict. (2 edn) 8: Slumming - Passing bad money.
1895		Crowe Aus. Sl. Dict. [as 1882].

3. (UK Und.) to fake illness.

1848

Flash Dict. in Sinks of London Laid Open 96: Abram, to sham, to slum, to pretend sickness.

4. to trick or cheat.

1873		Sl. Dict.
1881		Newcastle Courant 25 Nov. 6/5: She can slum things out at any time.
1890		‘Doss Chiderdoss’ ‘A Genteel Occupation’ Sporting Times 22 Feb. 1/2: The shopman was bored by Elizabeth’s aunt, / While his samples were slummed in Elizabeth’s bag.
1895		Crowe Aus. Sl. Dict. 76: Slum, [...] to cheat in doing work.
c.1905		J. Furphy Rigby’s Romance (1921) Ch. x: 🌐 When I got so disgusted with one book that I couldn’t face another line, I used to take a spell and then tackle some other [...] always marking the place where I knocked off, and never slumming a word.

5. (Aus.) to hide.

1895

Crowe Aus. Sl. Dict. 76: Slum, [...] to hide.

6. (US Und.) to drink.

1924

G. Henderson Keys to Crookdom 403: Drink. To quaff – slush up, swig, scoff, slum.

7. (US drugs) to sell inferior or fake drugs.

1997

L. Pettiway Workin’ It 120: You’ll get slummed, meaning they give you fake ’caine.