Green’s Dictionary of Slang

amusement gained at the expense of others.

[1800		Sporting Mag. Apr. XVI 21/1: Major Hawkes’s Ch. A. poney Fizgig].
1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 78: Fisgig—gig, or fun, made at or concerning another’s phiz, or face.
1841		D. Boucicault London Assurance in London Assurance and other Victorian Comedies (2001) Act III: He catches her in his arms and kisses her. Enter Lady Gay Spanker lady gay: Ha! Oh! [...] courtly: Fizgig! The devil!