The New Zealand Educational Institute is the largest education trade union in New Zealand. We come together as NZEI Te Riu Roa - New Zealand's largest education union, a Treaty-based organisation and a powerful advocate for quality public. As a member of NZEI Te Riu Roa you're part of an active and vibrant union working to ensure New Zealand children continue to get the high quality education. The New Zealand Educational Institute (NZEI, in Maori: Te Riu Roa) is the largest education trade union in New Zealand. Looking for online definition of NZEI or what NZEI stands for? NZEI is listed in the World's largest and most authoritative dictionary database of abbreviations and. Date of publication1993NotesNZEI SupplementAcknowledgmentNZEI Te Riu Roa.