From Wiktionary, the free dictionary
A corruption of the Sabir and Italian mezzo corona (“half-crown”).
madza caroon (plural madza caroons)
- (UK, obsolete slang) A half-crown coin; its value, 30 pence.
1859, J.C. Hotten, A Dictionary of Modern Slang, Cant, and Vulgar Words:Half-a-crown is known as an alderman, half a bull, half a tusheroon, and a madza caroon; whilst a crown piece, or five shillings, may be called either a bull, or a caroon, or a cartwheel, or a coachwheel, or a thick-un, or a tusheroon.
