1736 Canting Dictionary / R / RUM-Nab [thing]
a Beaver, or very good Hat.
· ·
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Entry taken from 1736 Canting Dictionary, by Nathan Bailey.
Rum Nab in the 1811 Vulgar Tongue
Also see examples in Canting Songs and Slang Rhymes collected by John S. Farmer (1896).