Green’s Dictionary of Slang

1. having a pleasant smell.

1890–1904

Farmer & Henley Sl. and Its Analogues.

2. (US) haughty, arrogant, disdainful; thus as adv. [var. on SE colloq. sniffy, disdainful, arrogant].

1883		Central New Jersey Home News (New Brunswick, NJ) 22 Sept. 4/2: He had some snifty old proffs [sic] there, bet your sweet life. Prof. Switzer could jerk a prayer out of him a yard long.
1889		K. Munroe Golden Days of ’49 188: If you notice me getting anyways snifty [...] you just bump me down hard once or twice.
1902		G.H. Lorimer Letters from a Self-Made Merchant to His Son xviii 268: Clytie said [...] that spirits were mighty snifty and high-toned [DA].
1924		C.J. Dennis ‘Introduction’ in Rose of Spadgers 12: An’ if yeh got a intro, I dare say / Yeh’d take it snifty an’ turn up yer nose.
1942		Berrey & Van den Bark Amer. Thes. Sl.

3. (US) general term of approbation [nifty adj.].

1950

Press & Sun-Bulletin (Binghamton, NY) 9 Apr. 6/2: ‘If all goes well I’ll be joinin’ ye soon with fifty snifty bucks in my paws’.