Definition of "rouf"

The betting also began to shift. "Sixpence Ned wins!" cried three or four; "Sixpence he loses!" answered another; "Done!" and up went the halfpence. "Half-a-crown Joe loses!"—"Here you are," answered Joe, but he lost again. "I'll try you a 'gen'" (shilling) said a coster; "And a 'rouf yenap'" (fourpence), added the other. "Say a 'exes'" (sixpence).—"Done!" and the betting continued, till the ground was spotted with silver and halfpence.

1851, Henry Mayhew, “Gambling of Costermongers”, in London Labour and the London Poor‎, volume 1, page 17

"Give me two gen, then, and take the whole bloody tol. I've walked me teef orf afore rouf this mornin', and wot 'ave I got? Two bloody yenneps! I ask yer."

1978, Rose Ayers, The Street Sparrows

Then the horse trading would begin with the words, from the jobber, of: "What's your size?" […] The broker might reply with the word rouf (a 4,000 share trade, which was a very small order); a score (20,000); a monkey (half a million); or a gorilla (one million shares - a very big order).

2011, Ian Lyall, The Street-Smart Trader, Harriman House Limited, page 11