Kawanatanga is a word from the Maori language (Maori are the indigenous people of New Zealand). The word first appeared in 1840 when the Treaty of Waitangi was being translated from English into Maori. It was used there to translate the concept of sovereignty, for which there was no existing suitable word in the Maori language at the time. The first part of the word, Kawana, is a transliteration into Maori of the English word governor. The suffix -tanga is very similar in meaning and use to the English suffix -ship, for example rangatiratanga (chieftainship) and kingitanga (kingship). So a literal translation of the word would be governorship.
The meaning attached to this word, and in particular how it relates to rangatiratanga is vital to discussion of the Treaty of Waitangi. This treaty is still vitally important in modern New Zealand, and remains the object of much controversy and political debate.