Green’s Dictionary of Slang

(orig. milit.) no matter, forget it.

1918		L.N. Smith Lingo of No Man’s Land 71: SANFAIRYANN An expression from the French ‘Cela ne fait rein,’ [sic] meaning the same as ‘Na-Poo;’ or in the opposite sense of ‘Jake;’ no good, done for.
1919		W.H. Downing Digger Dialects 43: san ferry ann (Fr., Ca ne fait rien) — It doesn’t matter.
1919		Sun. Times (Perth) 9 Mar. 7/3: ‘San fairy ann’ [the digger] turned into ‘san Mary Ann’.
1919		Dundee Courier 1 Nov. 8/3: You motto is ‘San Fairy Ann,’ / Your mission is to cheer.
1920		Derby Dly Teleg. 27 Jan. 2/4: Described as ‘the go one better’ revue, ‘Sweet Fanny Adams’ or ‘San Fari Ann,’ whichever way one reads the posters.
1921		N&Q 12 Ser. IX 425: Sally-Fairy-Ann. Variant for ‘sanfairyann’.
1921		Western Dly Press 12 Feb. 11/6: Banwell, who, when stopped for riding a motor bicycle without a rear red light [...] rode off after observing ‘sans fait rien,’ which the constable rendered as ‘Sans fairy Ann,’ was fined £1.
1924		(con. WWI) A.G. Pretty Gloss. Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: san-fairy-an. It does not matter, dont [sic] worry. Corruption of the French ‘Cela Ne Fait Rein.’ [sic].
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 253: Sand For Mary Ann: (French—ça ne fait rien): No matter; never mind.
1931		S.F. Hatton London’s Bad Boys 62: One example of this ‘san fairy ann’ philosophy will suffice.
1932		(con. WWI) L. Mann Flesh in Armour 121: ‘Tres bon for the troops. San-fairy-an’.
1941		Derby Dly Teleg. 21 June 8/4: On being taken to the police station [...] he was asked if he wanted another doctor. His reply was ‘sans fairy ann’.
1965		L. Haylen Big Red 193: He waved his hands expressively: ‘San Fairy Ann, as the boys say’.
1976		(con. 1944) J. Braine Waiting for Sheila (1977) 98: That’s san fairy ann to me.
2005		H. Mantel Beyond Black 164: [She] dropped dead two hours later in her trailer but san-fairy-ann, what’s that to me, and where’s my fiver?