Green’s Dictionary of Slang

an idler; thus doing quisby, not working, idling.

1837		Fraser’s Mag. Aug. 154: Hating still more a stop by such a quisby.
1838		Desmond Stage Struck IV i: That old quisby has certainly contrived to slink out of the house .
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor III 209/2: One morning, when we had been doing ‘quisby,’ that is, stopping idle, we hit upon another dodge.