Green’s Dictionary of Slang

1. the mouth.

1914

E. Pugh Cockney At Home 215: I wish you wouldn’t be so wonderful clever, knocking my Flor de Cabage out of my rosebud like that.

2. (US gay, also rosie) the anus.

c.1950		Nunnery versus Fuckery 17: He traced an erratic circle all the way round her tiny rose-bud anus.
1965		Guild Dict. Homosexual Terms 39: rosebud (n.): Rectum.
1972		B. Rodgers Queens’ Vernacular.
1994		G. Indiana Rent Boy 30: Looking down at some fashion designer’s rosebud gyrating on the end of my prick.
2003		K. Cage Gayle.
2015		‘Chelsea G. Summers’ in Vice 10 June 🌐 I can sense in anilingus terms as disparate as Australian (you are going down under, after all), rosie (after ‘rosebud’), lickety-split (self-explanatory), and tell a French joke (ditto).

3. (drugs) a distended, inflamed rectum after passing a painful stool, the result of extended opium or heroin use.

1973

Maurer & Vogel Narcotics and Narcotic Addiction in Maurer Lang. Und. (1981).