Green’s Dictionary of Slang

1. (US Und.) a senior figure in the US Mafia; thus capo de capo, capo di tutti capi, the supreme ‘boss of bosses’.

1955		H. Braddy ‘Narcotic Argot Along the Mexican Border’ in AS XXX:2 89: The Italian capo for the leader of a drug ring.
1969		(ref. to 1931)Ithaca Jrnl (NY) 7 Jan. 13/8: Maranzano [...] crowned himself ‘Capo di tutti capi’ — Boss of All Bosses.
1975		E. Torres Carlito’s Way 27: Every joke was played to some capo at ringside. [Ibid.] 56: Capo di tutti capi. Da’sa me. Ha!
1978		S. Longstreet Straw Boss (1979) 357: The Department of Justice identified him as capo de capo, boss of the bosses.
1985		N. Pileggi Wiseguy (2001) 97: Sebastian ‘Buster’ Aloi, the fifty-seven-year-old capo who ran the airport for the Colombo crime family.
1992		N. Stephenson Snow Crash (1993) 72: Especially now that they have black, Hispanic, and Asian capos who will respect your cultural identity?
2003		H. Hill A Good Fella’s Guide To N.Y. 8: The Capos are the middlemen, sometimes called skippers.
2004		Mad mag. Nov. 25: You’re gonna have stool pigeons ratting out capos with the fear of gettin’ whacked.
2010		Codella and Bennett Alphaville (2011) 44: It turned out that the pizza man was an old time capo who’d been around forever.
2017		D. Winslow The Force [ebook] Savino is a capo in the Cimino family.

2. in fig. use, any authority figure.

1973		B.S. Johnson All Bull 174: Strychnine was a corporal then, an anaemic National Service capo who got us to breakfast parade by seven-thirty every day.
1997		Bug (Aus.) 1 Oct. 🌐 That big problem, according to Hawke, was that workers were getting too big a slice of the economic cake and the capos were getting too little.

3. (UK Und.) a senior gangster.

2000		J.J. Connolly Layer Cake 68: This guy is a pal of an operator from across the border, a capo called JD.
2011		J.J. Connolly Viva La Madness 73: It then became the job of the capos to track back to shipping agents, enforcers, boat captains, loaders and suppliers.