Green’s Dictionary of Slang

(orig. US) a general intensifier, implying a greater flamboyance or exaggeration; allied to a variety of terms, e.g. boozeroo n.; smackeroos n.; stinkeroo n.

1899		Kipling ‘The Last Term’ in Complete Stalky & Co. (1987) 268: If King can make anything out of that, I’m a blue-eyed squatteroo.
1908		Sun. Times (Perth) 12 Apr. 1/1: No squateroo up there pays 7/6 without howling like a Hindoo.
1933		Hecht & Fowler Great Magoo 96: Makes kisseroos, tapping his lips the while with a romantic forefinger.
1935		Minneapolis Star (MN) 8 Oct. 11/3: ‘Boy, did I click on that last one! That was a $50,000 smackeroo’.
1936		(con. 1830s–60s) ‘Miles Franklin’ All That Swagger 349: She had no trouble in securing ‘jineroos’ to fill the place of her departed daughters.
1938		Flash! (Wash., D.C.) 21 Feb. 11/1: swingeroo—A dance that is a ‘killer-diller’ in every sense of the word both musically and pulchritudinally, not to mention the liquid phase.
1938		W. Winchell On Broadway 19 Dec. [synd. col.] ‘This Is New York’ was bulging with talent on its kick-off program, but it lacked the old zingeroo of showmanship.
1939		Detroit Free Press (MI) 17 Sept. 8/3: ‘Geemininy willikinazzy, a fellow can’t wear clean white shoes to a swingaroo like tonight, can he?’’.
1939		Cab Calloway ‘Hep! Hep! The Jumpin’ Jive’ 🎵 Now, don’t you be that ickeroo, / Get hep, come on and follow through.
1941		AS XVI:2 158: Gageroos, ‘gags’ in comic sense.
1941		B. Schulberg What Makes Sammy Run? (1992) 199: And then I came to what Sammy would call the topperoo.
1944		C. Himes ‘Let Me at the Enemy’ in Coll. Stories (1990) 43: That boll was some ickeroo ’cause it was doin’ some steps I ain’t never seen.
1944		D. Runyon Runyon à la Carte 88: You will find yourself in the canneroo.
1947		B. Schulberg Harder They Fall (1971) 14: Just one little lineroo about how the Cowboy is back in great shape. [Ibid.] 134: A blitzeroo [...] Well, that’s the phone bill .
1950		Goldin et al. DAUL 45/2: Clinkeroo. A clink, verbally underscored for emphasis. ‘Yeah, Blinker, that Holland County jug (jail) is a real clinkeroo.’ [Ibid.] 184/2: Saperoo. A very stupid person.
1952		W.R. Burnett Little Men, Big World 166: He’s got the shakeroos. He’s a lost cause.
1953		S. Bellow Augie March (1996) 81: The blood-smelling swaggeroos, recruits for mobs.
1953		W. Manchester City of Anger 124: I got a real zingeroo here, jest lahk last time.
1954		J. Thompson Swell-Looking Babe 126: Maybe it sounds like the old craperoo.
1956		‘Raymond Thorp’ Viper 31: The popularity of the new club soared to fantastic heights [...] it was a ‘smasheroo’.
1957		(con. 1943) A. Myrer Big War 9: Give us the old pooperoo.
1959		A. Sinclair My Friend Judas (1963) 39: Then I landed him the old sockeroo slap bang in the gin-trap.
1966		P. White Solid Mandala (1976) 18: You ought to move in with that pair of poofteroos across the road.
1968		(con. 1940s) G. Dutton Andy 21: ‘Come on,’ he motioned the forger to the bed [...] ‘Your turn old forgeroo.’ He held out his hand to help him on to the bed.
1972		R. Barrett Lovomaniacs (1973) 44: What a lot of juvenile crapperoo!
1974		‘P.B. Yuill’ Hazell Plays Solomon (1976) 39: Out there he had been responsible for four or five global smasheroos.
1976		Jenkins & Shrake Limo 289: ‘It was a smasheroo, remember?’ .
1979		J. Rechy Rushes (1981) 117: Well fuckeroo if that wasn’t a tribute to closetry.
1981		H. Gould Fort Apache, The Bronx 251: The old tosseroo ...
1983		C. Heath A-Team 2 (1984) 91: You and your three buckaroos.
1989		J. Healy Magill Apr. n.p.: Not since Dr Connor Cruise O’Brien condemned the Labour Party as ‘poltroons’ and ‘Uncle Paythers’ and then joined the party will we have seen so great a switcheroo [BS].
1991		(con. 1920s) O.D. Brooks Legs 109: Boots kept his end up by clipping the pinaroos in several bowling alleys.
1996		Eble Sl. and Sociability 40: Some sounds appear to give words a slangier flavor – most noticeably [...] the sound of oo replacing a vowel in words such as cigaroot from cigarette and bazooms from bosom or added to the end of a word like smasheroo from smasher.
2004		E. Weiner Drop Dead, My Lovely (2005) 76: ‘Look, never mind,’ she said – a neat switcheroo.
2005		Mad mag. July n.p.: But, eight years after the last stinkeroo, we’re being promised [etc.].
2010		J. Ellroy Hilliker Curse 37: It was a critical [...] dud and a paperback smasheroo.
2010		L. Berney Gutshot Straight [ebook] ‘I figured it was smarter to split up in case one of us got pinch-arooed’.
2020		C. Hiaasen Squeeze Me 265: ‘I don’t give a flying fuckeroo’.
2023		(con. 1962) J. Ellroy Enchanters 158: Lesser-known actresses displayed their ooga-booga, Full beaveroo, attached public hair.