In New Zealand, they form only parts of the majority (5)
I believe the answer is:
maori
'in' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for maori that I've seen before include "I roam (anag)" , "Polynesian aboriginal" , "A native from the south" , "Member of aboriginal people of New Zealand" , "Original New Zealanders" .)