Green’s Dictionary of Slang

1. a sleep.

1849		in S. Massett First Californian Troubador (1954) 25: I sought the comforts of a ‘bath,’ and a ‘lay down’.
1937		J. Curtis There Ain’t No Justice 9: He’s in the front room having a bit of a lay-down.
1957		J. Braine Room at the Top (1959) 89: Your uncle’s having a lay-down.

2. (US) a refusal or collapse [note lay down v. (1)].

1899–1900

C.L. Cullen Tales of the Ex-Tanks 20: When they finally told [...] that my first trip was to be to St. Louis, I was ready to do a lay-down.

3. (US) the deliberate loss of a sporting contest, usu. a prizefight.

1900

Nat. Police Gaz. (NY) 22 Sept. 11/4: Both Corbett and McCoy emphatically denied the charges of ‘fake’ and ‘laydown,’ claiming that the fight was on ite level.

4. a place to sleep; also attrib.

1909		cited in Partridge DU (1949).
1932		M. Marshall Travels of Tramp-Royal 96: I want to flop in a swell lay-down with knobs on.
1959		Mad mag. Sept. 41: A last lay-down pad for those that here conked out.

5. (US drugs) the price of admission to enter and smoke in an opium den; thus an opium den [lay down v. (3)].

1920		F. Williams Hop-Heads 110: The ‘smoker’ pays $1 a card and $1 for his ‘lay down’ and ‘lay out,’ use of the bunk and opium lamp and pipes.
1936		D. Maurer ‘Argot of the Und. Narcotic Addict’ Pt 1 in AS XI:2 123/2: lay-down. The price an addict pays for a lay in a den.

6. (UK Und.) a period of remand in prison.

1936		J. Curtis Gilt Kid 278: First they’ll give me a laydown at Brixton while they run the rule over me and then remand me to the Old Bailey.
1941		V. Davis Phenomena in Crime 249: Joe’s gone for a lay-down.
1959		‘The Pickpocket’ in Encounter n.d. in Norman Norman’s London (1969) 66: The fourpenny snore and the sweeny / Dwell in the box for you. / So nitto, nark it, stoppo, / Or a carpet’s a lay-down for you.
1977		D. Powis Signs of Crime 191: Lay down A remand in custody.
1988		J. Healy Grass Arena (1990) 105: We saw the head-shrinker at Brixton [...] He put us down as chronic alkies. Then we had a three-week laydown.

7. (US) a certainty [one can lay down money on it].

1935		A.J. Pollock Und. Speaks.
1937		R. Westerby Wide Boys Never Work (1938) 119: Watch him doddle home, they said. He had the breeding, he had the speed. It ought to be a lay-down.

8. a burial.

1958

Mad mag. Jan.–Feb. 48: Come I to make this gig at Caesar’s lay-down.