Green’s Dictionary of Slang

1. the off-cuts from a butcher’s preparing of meat for sale.

1923

J. Manchon Le Slang.

2. (UK/US tramp, also schackles) soup [note Irwin, American Tramp and Und. Slang (1931): ‘No doubt the word was coined in some prison where the dish was of such a nature as to keep the prisoners near a toilet, or ‘shackled’ to one place. It is generally used on the road to indicate any article of food that exercises a definite effect upon the elimination’].

1909		W.H. Davies Beggars 213: They are always washing clothes and making shackles.
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 254: Shackles: Soup: stew.
1926		W.H. Davies Adventures of Johnny Walker 155: They would not let the smell of their shackles reach the nose of a true beggar, if they could prevent it.
1931		E. Blair ‘Hop-Picking Diary’ 19 Sept.–8 Oct. in Complete Works X (1998) 230: Shackles . . . broth or gravy.
1933		‘George Orwell’ Down and Out in Complete Works I (1986) 176: These (omitting the ones that everyone knows) are some of the cant words now used in London: [...] Shackles — soup.
1949		Monteleone Criminal Sl. (rev. edn) 201: schackles Soup.

3. (US) cheese [cheese is trad. ‘binding’].

1949

Monteleone Criminal Sl. (rev. edn).