Green’s Dictionary of Slang

knife n.

SE in slang uses

In compounds

knife-thrower (n.) [the laying of tables]

(US) a waiter or waitress.

1905

Smart Set Oct. 3/1: ‘They got a new knife-thrower up to the hotel,’ he announced by and bye [...] (A ‘knife-thrower’, be it known, is parlance for waitress.) .

In phrases

like a knife (adv.)

(US) very quickly.

1836		N.Y. Herald 15 Aug. 2/4: [William Robinson, sentenced to ten years]: That’s no time at all, I can live it out like a knife.
1916		J. Buchan Greenmantle (1930) 159: If I were to buy a pair of false whiskers and dye my hair and dress like a Baptist parson and go into Germany on the peace racket, I guess they’d be on my trail like a knife.