Green’s Dictionary of Slang

caboose n.

[Du. kabuis, a cook’s galley; briefly used in 18C/19C UK naval jargon to mean a galley, but thereafter appears only in US. Thence SAmE caboose as adopted in the American West to mean the cow-hide container stretched across the rear of the chuck wagon, which, when full, hangs down behind the wagon; thence it was used by the railroads to mean a wagon (usu. attached to a freight train) in which the crew could eat, sleep and cook]
(US)

1. as a small room.

(a) a cubby-hole, a small room.

[US]Congressional Globe 15 Feb. Appendix 343/1: We have a postmaster in our own little village [...] and in his little caboose of a post office I have found electioneering interferences [DA].
[UK]Sl. Dict. 106: Caboose a term used by tramps to indicate a kitchen.
[Aus]Bulletin (Sydney) 11 Aug. 43/2: It was only a blind so that I could get the yellow stuff away in the billy. If I hadn’t built that new caboose they’d never have smelt even the rat I put through the drain to fix my string!
[Aus]Bulletin (Sydney) 14 Nov. 47/2: We scattered all the fiends of ’Ell; we let the Devil loose; / But Bill ’e was a credit to that spirit’ous caboose!
[US]M.G. Hayden ‘Terms Of Disparagement’ in DN IV:iii 203: caboose, any small place.
[Aus]C.J. Dennis ‘In Spadger’s Lane’ in Moods of Ginger Mick 71: Low down, a splotch o’ red, where ’angs a blind / Before the winder uv a Chow caboose.
[UK]D. Bolster Roll On My Twelve 48: A ‘caboose,’ that is, a little hole, a store or an issue-room, is the thing for which every older rating yearns.
[US]L. Pettiway Honey, Honey, Miss Thang 223: My dad put me inside a caboose, and the caboose was full of rats.

(b) any form of place or room.

[Aus]Bell’s Life in Sydney 1 June 3/2: Polly, with affectionate solicitude, invited him to her caboose.
Opelika Times 30 Sept. n.p.: A colored man [...] should be preferred as tenant of our houses, cabooses on the farm, drayman upon the streets [DA].
[Aus]Crowe Aus. Sl. Dict. 14: Caboose, a lodging-house.
[UK]J.D. Brayshaw Slum Silhouettes 55: ‘And a very comfortable little caboose she’s got,’ said Bill.
[UK]J. Masefield ‘A Night at Dago Tom’s’ in Salt-Water Ballads 38: We scooted south with a press of sail till we fetched to a caboose.
[US]J. Lait ‘Canada Kid’ in Beef, Iron and Wine (1917) 181: It’s got me wingin’, too. I keep right on workin’ — I lift a boob for $106.60 on a mainstem caboose yesterday.
[UK]‘Sapper’ Bulldog Drummond 247: The mistake you’ve made [...] is not giving Peterson a seat in your Cabinet. He’d have the whole caboose eating out of his hand.
[Aus]C.J. Dennis ‘’Ave a ’Eart!’ in Rose of Spadgers 77: If I ’ad not cut loose / In Spadgers, in them days long, long deplored, / ’Ow could I knowed the run uv Foo’s caboose?
[Aus](con. 1830s–60s) ‘Miles Franklin’ All That Swagger 149: Molly’s heart is scalded for ye, and if ye’r father will put up a little caboose for ye, Oi’ll set ye up rint free.
[UK]A. Liddell Hart Strange Company 157: The large, blond German corporal in charge of the cook-house had also got a caboose inside the camp where he lived with his assistant .
[UK]M. Amis London Fields 31: Lying in sleep’s caboose, seconds before Marmaduke woke him with a clout.

(c) a prison.

[UK]C.M. Westmacott Eng. Spy II 217: May I be bolted into old Belzy’s caboose if she be a copper fastening the better for Jem Buntline!
[UK]Leaves from Diary of Celebrated Burglar 29/1: While on the way to the ‘caboose’ Joe’s courage began to drop, for he saw but little chance of getting out of the scrape he was in.
[US]T.J. Hains Mr Trunnell Mate of the Ship ‘Pirate’ Ch. iii: ’Twould ha’ been no mutiny to override the new skipper, an’ land th’ other in th’ caboose.
[US]M. Bodenheim Georgie May 28: She’d land both of us in the caboose.
Federal Writers Project These Are Our Lives 346: it’s going to be kept clean as long as I’m there if they put me in the caboose for cruelty to roaches and water bugs [DA].
[US]R. Chandler Farewell, My Lovely (1949) 14: Where you figure I been them eight years I said about? [...] In the caboose.
[US]Mad mag. June–July 22: Throw him in the caboose and report for your next assignment.
[US]Wentworth & Flexner DAS.
[Aus]K. Willey Naked Island 116: The policeman clicked on the handcuffs and escorted me ashore. I went into lodgings at the local caboose.

(d) in fig. use, penury; i.e. reduced to poor living circumstances.

[US]‘Hal Ellson’ Tomboy (1952) 95: Then you’d be broke [...] Right back in the caboose.

2. in the context of the rear.

(a) the buttocks, the behind; occas. the back.

in Winterich Mlle. from Armentières n.p.: She waggled her headlights and caboose.
[US]C. Panzram Journal of Murder in Gaddis & Long (2002) 24: He fell on his big fat caboose with his mouth wide open.
[US]A.J. Barr Let Tomorrow Come 41: He gives me one look an’ hauls his caboose back up to the stem.
[US]L. Hoban ‘Time to Kill’ Crack Detective Jan. 🌐 I bent over, turning the caboose to the blonde and the gat.
[US]N. Algren Walk on the Wild Side 25: You must be connected wit the railroads [...] you got such a perty caboose.
[US]‘Iceberg Slim’ Pimp 164: He drove his needle-toed shoe into her wide caboose.
[US]‘Iceberg Slim’ Airtight Willie and Me 44: He nearly tripped himself gazing at Sue’s caboose.
P. Gable In Bondage Schoolgirl n.p.: ‘Yeah, baby, back it up, come on, move that fuckin’ caboose!’ Gino said, slapping her with both opened palms harder and harder while his groin slammed against her ass.
[US]‘Victoria Parker’ Pay for Play Cheerleaders 🌐 He cupped her teen-dream ass. [...] ‘Awwwww, shit!’ Chrissie cried. ‘He’s lickin’ my caboose!’.
[US]R.O. Scott Gay Sl. Dict. 🌐.
[US]S. Morgan Homeboy 135: She’s got a sexy caboose.
‘Teaser Pulls a Train’ at www.asstr.org 🌐 ‘Then the last guy gets the caboose.’ She didn’t understand that. ‘The last guy does you up the ass.’.

(b) a slow-witted person.

[US]Hecht & Bodenheim Cutie 40: For a few minutes this flat wheeled caboose of gloom couldn’t figure out which part of him was his feet.

(c) the last child in a family [also puns on SE papoose].

[US] in DARE.

(d) a person who continually follows along behind, a hanger-on [note milit. j. caboose, the last man in a line of patrolling troops, opposite of point].

[US]in DARE.

(e) (US campus) the last man in a session of group sex.

[US] in Current Sl. IV:3–4 (1970).