Green’s Dictionary of Slang

(N.Z.) a friend, a member of one’s extended family; also attrib.

1990		Listener (NZ) 11 June 14: [headline] Cuzzybro Comedy [DNZE].
1992		A. Duff One Night Out Stealing 53: I knew this was it, cuzzy; we are gonna be getting it on.
2003		McGill Reed Dict. of N.Z. Sl. 57: cuz/cuzzy/cuzzy bro Polynesian male greeting. Pakeha term for a Polynesian male. From late C20.
2006		posting at au.messages.yahoo.com 27 Feb. 🌐 & then we’ve got 2 work out – who has the Maori/kiwi relatives...cos somebodies got to be my ‘cuzzybro’ LOL.