Green’s Dictionary of Slang

stop! beware!

1873		Sl. Dict. 234: nantee also means ‘shut up’ or ‘leave off!’.
1886		Sporting Times 10 Apr. 3/3: Once or twice I ses, ‘Nanty, gents, nanty’.
1893		R. Morton ‘O Lizer, Para-Lizer’ 🎵 Lizer murmured ‘nanty’ – I want to kiss your brother Fred.
1900		Sporting Times 6 Jan. 1/4: ’Ere, nanty, now, nanty! [...] don’t start no ’anky-panky with me or I shall dot yer!
1901		A. Binstead More Gal’s Gossip 83: Nanty! Don’t put it about, but it’s a pinch — Honeymoon!
1910		‘Doss Chiderdoss’ ‘Woman’s Wear’ Sporting Times 30 July 1/3: If fashion says ‘Nanty’ you’ll alter your mien.
1934		P. Allingham Cheapjack 123: I doubled him up to quids. ‘Nanty!’ he said.