Green’s Dictionary of Slang

(N.Z.) drowning.

1947		H. Beattie Early Runholding in Otago 24: In the early days [before bridges were built] [...] so many persons were drowned that drowning was often described as ‘the New Zealand Death.’ [DNZE].
1960		(ref. to 1860s) Over Whitcombe Pass 15: Drowning was, in those days called the ‘national death’, so often did glacier-fed mountain rivers claim victims [DNZE].
1971		(con. mid-19C) G.J. Griffiths King Wakatip 73: When the diggers came, the ‘New Zealand death’ – as drownings came to be termed – rose to epic proportions [DNZE].
1984		E.T. Beardsley Blackball 08 70: Drowned in a river – the New Zealand death [DNZE].

(N.Z.) indigenously grown marijuana.

2003

McGill Reed Dict. of N.Z. Sl.

(N.Z.) pork.

1887		Auckland Weekly News 17 Sept. 8: My first meal was New Zealand mutton [...] I found out afterwards that was the name given to pork [DNZE].
1897		P.A. Philips Memories of the Past 38: I recollect [...] being served with what looked like very white meat; and, asking what it was, was told ‘New Zealand mutton’, and it was some time before I was undeceived [DNZE].