Green’s Dictionary of Slang

multee kertever adj.

very bad.

1844		New Sprees of London 12: [T]he rumcul of the casey is a crabby bloke, and the lush multa catava.
1859		Hotten Dict. of Modern Sl. etc. 65: Multee kertever very bad.
1861		Melbourne Punch ‘City Police Court’ 3 Oct. 234/1: The Mayor. – Well my flying sawney hunter [...] you were reported to me as being scammered with some multee kertever flue fakers in a flatty ken.
1873		Sl. Dict.
1887		Sat. Rev. (London) 14 May 700: We know how to make the ghost walk when biz is rumbo, and what it is that makes the company multicattivo [F&H].