Green’s Dictionary of Slang

floor n.

SE in slang uses

In compounds

floor boy (n.) [one who stays, fig, at ground level]

(US black) a boring individual, one who does not get high adj.1

Chief Keef ‘Hate Bein’ Sober’ 🎵 On my tour bus we get dumb high you’s a floor boy.
floor-flapper (n.)

(Aus.) a floor-walker in a large store.

[Aus]Referee (Sydney) 12 Sept. 9/2: A highly proper and pompous party who [...] acts as shopwalker— or floor-flapper, as the vulgar term it.

In phrases

go to the floor (with) (v.)

(US) to attack physically.

[US]Anaconda Standard (MT) 10 Apr. 8/7: You fellows come along and see me give him his trimmings. [...] I’m going to the floor with him right now.
on the floor

1. drunk.

[UK]Sporting Times 12 May 2/1: Twenty-four hours after the first-named had ridden Leamington to victory, the two were ‘on the floor,’ stretched senseless on the sward.

2. beaten.

[UK]R. Westerby Wide Boys Never Work (1938) 202: It’s licked you, Jim. You’re on the floor.

3. poor; thus also as n. in cit. 2002 [rhy. sl.].

[UK]E. Pugh Cockney At Home 162: Whereas if I answered you, ‘On the floor!’ an’ pulled a face like a farden kite, you’d all ha’ groaned in symperfy.
[UK]G. Kersh Night and the City 61: If you’re on the floor, come to me and you’re always sure of a ten-pound note.
[UK]R. Llewellyn None But the Lonely Heart 104: ‘I’m on the floor,’ he says. ‘Out of work.’.
[UK]‘Charles Raven’ Und. Nights 168: You told me yourself the geezer was on the floor.
[UK]F. Norman Guntz 214: He was dead skint and on the floor.
[UK]J. Jones Rhy. Cockney Sl.
[UK](con. 1930s) Barltrop & Wolveridge Muvver Tongue 18: A hard-up person is [...] ‘on the floor’.
[UK] in R. Graef Living Dangerously 110: If it weren’t for his parents he’d be on the floor.
[UK]M. Coles More Bible in Cockney 13: I’m gonna bring some great news for all the on-the-floor.
stick to the floor without holding on (v.) (also lie on the floor...)

to be (very) drunk.

[US]M.L. Weems Drunkard’s Looking Glass (1929) 60: The drunkard’s looking glass, reflecting a faithful likeness of the drunkard, in sundry very interesting attitudes, [...] as first, when he has only ‘a drop in his eye;’ second, when he is ‘half shaved;’ third, when he is getting ‘a little on the staggers or so;’ and fourth, and fifth, and so on, till he is ‘quite capsized;’ or ‘snug under the table with the dogs,’ and can ‘stick to the floor without holding on.’.
[UK]Sportsman (London) ‘Notes on News’ 8 July 4/1: [A] poor fellow who was simply ‘happy’ — one who, in his own opinion, is not drunk until he cannot lie on his back comfortably without holding on to something.