C-note, n. — Green’s Dictionary of Slang

C-note n.

1. (US) a $100 bill.

1929		C. Panzram Journal of Murder in Gaddis & Long (2002) 171: Some skunk [...] can be hired for a C note or less to bump him off.
1939		R. Chandler ‘Pearls Are a Nuisance’ in Spanish Blood (1946) 109: ‘Put a C-note on the table.’ I took my wallet out and extracted from it one of the two hundred-dollar bills.
1943		W. Brandon ‘Its so Peaceful in the Country’ in Ruhm Hard-Boiled Detective (1977) 323: She asks me, will I really come back, and I tell her I cross my heart for a C note I will come back on the hour.
1956		N. Algren Walk on the Wild Side 144: Sure enough, folded neatly quartered, so as to let him read the ‘100’ without unfolding it, Finnerty’s c-note still waited to be spent.
1968		T. Thackrey Gambling Secrets of Nick The Greek 243: The hustler laughed and refused Nick’s extra C-note.
1979		‘Iceberg Slim’ Airtight Willie and Me 18: He saw Willie let fall and retrieve our lone ‘C’ note.
1981		J. Ellroy Brown’s Requiem 23: There must have been sixty or seventy C-notes.
1990		J. Ellroy ‘Gravy Train’ in Pronzini & Adrian Hard-Boiled (1995) 490: They walked out thumbing C-notes.
1998		L. Stringer Grand Central Winter (1999) 124: Richard [...] triumphantly returns, clutching a check for seven grand, and hits me off with a C-note.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 44/2: C-note n. a $100 note.
2007		C. Goffard Snitch Jacket 172: Spot me a C-note?
2019		S.M. Jones Lives Laid Away [ebook] ‘When was the last time you heard of some government grunt whippin’ out a C-note for anything?’.
2020		S.A. Crosby Blacktop Wasteland 167: ‘White went out and got a Corvette and started dropping c-notes at Danny’s bar’.

2. (US prison) a 100-year jail sentence.

1971–2

C. Shafer ‘Catheads [...] and Cho-Cho Sticks’ in Abernethy Bounty of Texas (1990) 201: C- note, n. – a hundred-year sentence.

3. (US black) a one-year sentence.

1985

T.R. Houser Central Sl. 15: C-note A jail sentence of one year.