Green’s Dictionary of Slang

sarcasm.

1905		Sporting Times 15 Apr. 1/3: [He said] as he’s a retired gentleman. ‘Dear, dear!’ says Sir Alfred, slippin’ Dad a bit o’ sarc, ‘havin’ once attained that distinction, what on earth made yer relinkish it?’.
1915		‘Doss Chiderdoss’ ‘Glasses’ Sporting Times 23 Jan. 1/2: Tooral’s eyeglass invited Tollolover’s ‘sarc.’ / ‘What’s the good of that thing?’ bantered he.