Green’s Dictionary of Slang

putrid, stinking, ‘off’.

1859, 1860		Hotten Dict. of Modern Sl. etc.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 23/2: Kennetseemo ... Stinking.
1873		Sl. Dict.
1977		D. Powis Signs of Crime 190: Kennetseeno Smelly, the stench of decomposition; sometimes said when a person breaks wind: ‘Kennetseeno!’ (London backslang for ‘stinking’.).