Green’s Dictionary of Slang

1. zilcho, zero, nothing, unimportant; also as adj.

1922		N.Y. Times 27 Aug. sect. 6 1: This sweet ballad has a rather involved scenario about a widow who is driving away from the burial services of her husband (the late Joseph Zilch) when, in the coachman she recognizes an old sweetheart.
[1931		Ballyhoo I. I. 1 (heading) n.p.: President Henry P. Zilch. Chairman of the Board Charles D. Zilch. Treasurer Otto Zilch] [OED]].
1965		J. Thompson Texas by the Tail (1994) 11: Mitch knew it was strictly zilch.
1968		‘Hy Lit’ Hy Lit’s Unbelievable Dict. of Hip Words 52: zilch – Double talk.
1979		E. Torres After Hours 187: All their money and connections and they came up with zilch.
1982		P. Redmond Tucker and Co 84: The magazines had scored a zilch in the inspiration department.
1990		R.G. Barratt ‘Real Men Save Whales’ in What Do You Reckon (1997) [ebook] [Y]ou know what thanks and support they get from governments the world over? Zilch.
1993		T. Jones Pugilist at Rest 179: What lies on the other side? [...] – zilch. And zilch wasn’t that bad. What was wrong with zilch?
1998		I. Welsh Filth 185: What do they know? Nothing. Zilch. Sweet fuck all.
2005		L. Redhead Rubdown [ebook] You know what I felt? [...] Nothing. Zip. Zilch.
2007		C. Goffard Snitch Jacket 78: ’Course he never did zilch with himself.
2009		(con. 1960s) J. Ellroy Blood’s a Rover 23: He scanned the street [...] Ziltch — just some old hebes loping to shul.
2012		(con. 1980s) I. Welsh Skagboys 119: Janey’ll still get something, but it’ll be reduced tae almost zilch.
2015		S. King Finders Keepers (2016) 14: There’s nothing. I mean zilch.
2019		G. Disher Peace [ebook] He checked for mobile reception — zilch.
2020		C. Hiaasen Squeeze Me 47: You’ve got nothing. Zilcho-o.
2021		J. Ellroy Widespread Panic 91: I checked [...] for stashed booty and got zilch.
2023		A. Parks To Die in June 105: ‘[C]hances of him letting anything slip are zilch’.

2. an ordinary or insignificant person.

1953		R. Prather ‘Double Take’ in Best of Manhunt (2019) [ebook] ‘The guy I know as Harrison, you know as Klein; his girl friend calls him John, and his real name is probably Willie Zilch’.
1967–8		Baker et al. CUSS 226: A person without much social or academic ability.
1969		Current Sl. III:4 11: Zilch, n. A nobody.
2024		J. Meades Empty Wigs (t/s) 855: [T]he criminals themselves are...I was going to say nobodies, zilches.