It's usually called Te Reo (the language) and it means Maori - Te Reo Maori.
Palmerston North's Maori name is Te Papa-i-oea. And I am trying to find out what that means. It is suprisingly hard to do.
This city is in the Manawatu and I have found out what that means. Manawa is heart and tu means stops. Thus - The heart stops. Obviously the heart stops with delight at the beauty of the landscape.
This is a quote from a website but I have seen different stories on other websites.
"The explorer who named the Manawatu River was named Hau. He was travelling down the coast from Taranaki following his wife Wairaka who had run off with her lover. By the time he reached the Manawatu Hau had crossed several rivers, but Hau was afraid he would not be able to get across this big, wide river and so he named the river Manawatu, meaning "heart standing still"."