butterfly, adj. — Green’s Dictionary of Slang

butterfly adj.

of clothes, gaudy, tasteless, flashy.

1900

‘Doss Chiderdoss’ ‘Her New Game’ Sporting Times 29 Sept. 1/4: She was usually just a little ‘loud’ in her attire [...] But the other day a change came o’er the spirit of her dream, / For she threw aside her butterfly rig-out; / And apparelled in far better taste, she really looked the cream / Of society.

In compounds

butterfly man (n.)

(US) a flamboyant male homosexual.

c.1926		‘K. Curtin’ We Bulgarians (1987) 68: One [play] is by a Frenchman, Jacques Natanson, the title of which translates into something like The Butterfly Man! and the other by an American which is called The Drag [Simes:DLSS].
1934		L. Levenson Butterfly Man half-title: In Texas, Ken Gracey was a normal young man….His transformation into the flaming Butterfly Man, darling of the Third Sex, who rockets through riotous revels from Coast to Coast, is the tragic tale of the youth who never knew himself until too late [Simes:DLSS].

butterfly-queen (n.)

(US gay) one who enjoys mutual fellation.

1972

‘Homosexual argot’ in Anthrop. Linguistics 14 191: butterfly queen, n. A male homosexual who enjoys both receiving and performing fellatio at the same time [Simes:DLSS].