Green’s Dictionary of Slang

(Anglo-Irish) food, sustenance.

1841		Comic Almanack Mar. 262: Close behind his benevolent face, / And belly and back, as he’s taking his whack, / Good Master Clown is making grimace.
c.1850		‘Wakefield Gaol’ in R. Palmer Touch of the Times 251: With skilly and whack in Wakefield Gaol.
1865		‘The County Jail’ in I. Beadle Comic and Sentimental Song Bk 55: Service being over we all got back, / And fell in line for skilly and whack.
1882		Dundee Courier 4 July 7/5: When you’re eating your skilly and whack.
1899		Kipling ‘Slaves of the Lamp — Part II’ in Complete Stalky & Co. (1987) 284: We hadn’t any grub for our men, and Stalky had only four days’ whack for his.
1910		P.W. Joyce Eng. As We Speak It In Ireland.