Green’s Dictionary of Slang

1. (Aus.) a slender beer glass, with an ‘hour-glass’ shape; the drink served in such a glass [used fig. to reflect the size of the glass].

1940		Argus (Melbourne) 7 Dec. 8/1: There’s abso-bally-lutely no extra charge on medium glasses, ponies, or pixies; yet that doesn’t silence ’em up, at Junee, where men are men and a beer means a schooner.
1945		Baker Aus. Lang. 169: Lady’s waist (Sydney) and pixie (Melbourne) for a small glass of beer also appear to be Australian originals.

2. (also pix) a homosexual man [var. on fairy n.¹ (3)].

1937		J.M. Cain Serenade (1985) 257: ‘He was a pixie, but he was also a musician [...] he asked us to his house-warming—’ ‘Are you a pix?’.
1941		G. Legman ‘Lang. of Homosexuality’ Appendix VII in Henry Sex Variants.
1965		Guild Dict. Homosexual Terms 36: pixie (n.): A homosexual male, as seen by the heterosexual (an exception if used; see fairy).
1972		B. Rodgers Queens’ Vernacular 73: stereotype effeminate homosexual [...] pix (rare, hetero sl reinforced by use of the slur fairy). [Ibid.] 149: pixie 1. (hetero sl) homosexual with an elfin look.
2003		K. Cage Gayle.

3. (US black) straightened hair on a man.

1972

D. Claerbaut Black Jargon in White America 75: pixie n. a processed or straightened hairstyle.