Green’s Dictionary of Slang

whiz n.¹

1. noise, commotion, a ‘buzz’.

1793		Sporting Mag. Nov. III 104/1: Make your exit in a whiz – dam me!!!
1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 194: Whiz buz, or noise, interruption of tongues.

2. (US) a (drunken) spree.

1902		C.L. Cullen More Ex-Tank Tales 40: He didn’t propose to have anybody abandon him to gloom [...] when he started out to have a little teeny bit of a whizz.
1906		Wash. Post (DC) 30 Dec. 12/1: [I]t’s a dickens of a town where a man can’t pop in a few drinks and go out for a litle whizz.
1907		‘O. Henry’ Trimmed Lamp (1916) 240: He’s going on a whiz to-night .

3. (Aus.) energy, spirit.

1951		D. Stivens Jimmy Brockett 145: All rich men’s sons [...] no more whizz in the lot of them than in a dead sheep.
1976		J. Braine Waiting for Sheila (1977) 17: The owner, an advertising whizz-kid in his thirties, was running out of whizz.

In compounds

whiz pop (n.) [they emulate a dud firework, which whizzes then sputters out with an anti-climactic pop]

(US campus) a stupid person.

1975

G. Underwood ‘Razorback Sl.’ in AS L:1/2 69: whiz-pop n Person regarded as stupid.

whiz wagon (n.)

(US) an automobile.

1904		‘Hugh McHugh’ I’m from Missouri 60: And thus they started out in the whiz wagon.
1906		S. Ford Shorty McCabe 118: First we’d jog a few miles, then hop aboard the whiz-wagon and spurt for running water.
1914		‘Hugh McHugh’ You Should Worry cap. 2: And away they started in the Whiz Wagon.

In exclamations

hold your whiz!

be quiet! shut up!

1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 194: Hould your whiz there in the shilling gallery, you sixpenny half-price marms.
1902		H. Baumann Londinismen (2nd edn).