Green’s Dictionary of Slang

1. brisk, lively, smart.

1611		Middleton & Dekker Roaring Girle I i: What are your whisking gallants to our husbands.
1662		Jack Adams, his perpetual almanack (2 edn) 6: [I shall] give the World an account of that whisking fellow [...] almost as handsome as myself.
1681		T. Flatman Heraclitus Ridens No. 40 (1713) II 2: If you talk of Rubbers and Whiskers, [...] he’s a whisking Rubber for you; [...] he can rub one Man into two [OED].
1824		T. Carlyle letter 23 June in Froude T. Carlyle (1882) 218: Captain Smith was [...] brisk, lean, whisking, smart of speech, and quick in bowing .
1840		T. Haliburton Clockmaker III 294: A’most an excellent wife, dependable friend, and whiskin’ housekeeper you have made to me.

2. great, excessive.

1673		Head Canting Academy 166: They have whisking water-works for evacuation.
1681		E. Hickeringill News from Colchester in Works (1709) I 394: With what astonishment the People of Colchester were struck, when they read [...] this Whisking Lye.
1707		Humours of a Coffee-House 2 July 16: A Jury wou’d give you whisking Damages, especially when spoke against a Man in his Business.
1715		‘Nickydemus Ninnyhammer’ Homer in a nut-shell 4: With an huge whisking Quiver fhoulder'd, / For want of using, almost moulder’d.