Green’s Dictionary of Slang

(orig. US) a lot of, many.

1942		Berrey & Van den Bark Amer. Thes. Sl.
1948		Grenville News (SC) 2 Jan. 19/1: The Big Blizz cost mucho loot.
1958		(con. 1950) E. Frankel Band of Brothers 101: I got mucho troubles of my own.
1962		Kerouac letter 8 June in Charters II (1999) 341: Have mucho hot coffee, cup after cup.
1972		O. Hawkins Ghetto Sketches 56: Mucho thanks, good brother.
1989		(con. 1982–6) T. Williams Cocaine Kids (1990) 60: I snatched mucho beads that night.
1993		R. Shell Iced 70: It’s like a gangster with an Uzi. You’ve got mucho juice.
2003		N. Griffiths Stump 59: The safe in there’ll be fuckin chocka. Muchos swag.
2011		J.J. Connolly Viva La Madness 143: He’s dropping the girl running the VIP [...] mucho casho to sort him out a booth.