Green’s Dictionary of Slang

1. (also cully-rumper) a pimp.

1660		‘Peter Aretine’ Strange and True Newes title: The unparralleld Practices of Mris Fotheringham, her whores, Hectors and Rumpers. [Ibid.] 4: Ordered that such as pick their Rumpers pockets when they be drunk deny it to them when they are sober for the credit of our good-old-cause.
1660		Wandring Whore II 8: I was told that [she] stood upon her head with naked breech and belly whilst four Cully-rumpers chuck’t in fifteen Half-crowns into her Commodity.
1660		‘Peter Aretine’ Strange and True Newes 2: One of the Society do stand upon their heads [...] with all their cloathes and smock about their ears bare breeches to the cold wall [...] leggs spread at large, with the door of their Chuck-office open, because that fashion was lately invented by Mrs Fotheringham for her Cully-rumpers to chuck half crown’s in .
a.1661		‘Arsy Versy’ in Rump Poems and Songs (1662) ii 51: Lord Mounson? Oh Venus! what do you here? I little thought you were a Rumper I swear.

2. a prostitute’s customer.

1660

‘Peter Aretine’ Strange and True Newes 4: Ordered that such as pick their Rumpers pockets when they be drunk deny it to them when they are sober for the credit of our good-old-cause.

3. a prostitute.

1937–84

Partridge DSUE (1984) 999/2: C.19.

4. (Aus.) the buttocks.

1843

Satirist & Sporting Chron. (Sydney) 4 Mar. 3/2: Mrs Llewellyn’s fair hands are made very rough by rubbing up Sam’s Rumpers.