Green’s Dictionary of Slang

1. (US) a fivepenny bit, the nickname for the Spanish half-real, worth about 4½ cents or 6 cents in some states; thus as a term for any worthless thing in phrs. such as not care a fip.

1822		Phila. Freeman’s Journal 5 Sept. n.p.: A dispute now commenced between two persons respecting some cents and a ‘fip,’ which had fallen from his pocket [DA].
1828		R.M. Bird City Looking Glass I iii: Here’s one poor copper; ’tis all I have earned to day. So, if you’ll deliver me a fip, I’ll change it.
1836		D. Crockett Exploits and Adventures (1934) 167: ‘How much do you charge,’ said I, ‘when you retail your liquor?’ ‘A fip a glass.’.
1845		G.W. Harris ‘The Knob Dance’ Spirit of the Times (N.Y.) XV July in Inge (1967) 46: He [...] only axes a ‘fip’ for a reel, and two ‘bits’ fur what corn-juice you suck.
1857		Oregon Weekly Times in DN IV :ii 133: ‘Do you want any meal, ma’am?’ ‘What do you ask for a bushel?’ ‘Ten cents, ma’am, prime.’ ‘O, I can get it for a fip.’.
1864		in R.G. Carter Four Brothers in Blue (1978) 19 June 440: I must still run the bloody gauntlet, my life not worth a ‘fip’.
1872		Schele De Vere Americanisms 291: The Spanish silver coins [...] have nearly all disappeared, and with them their local names, as the fip and the levy, coins representing six and a quarter, and twelve and a half cents, the former a contraction of five pence through the English fippence.
1891		S.M. Welch Recollections of Buffalo 1830–40 169: It was common, particularly in New England, to call a sixpence or half a dime, a fip.
1909		Carr & Chase in ‘Word-List From Aroostook’ in DN III:v 411: fip, n. Five pence. ‘I don’t care a fip.’.
1937		(con. early 19C) News-Sun (Newport, PA) 1 July 8/1: ‘Fip’ was a slang term used during early American hisatory to denote a monetary value of 6¼ cents. Two fips equated a bit, a shilling, worth 12 cents.
1989		C. Hyatt When Me Was A Boy 122: Plenty of us boys woulda put ‘fip’ – that’s threepence or six cents if y’like – inna Son palm.

2. see fippence n.