Green’s Dictionary of Slang

(N.Z.) on a journey, an opportunity to stop and use a lavatory.

1988		McGill Dict. of Kiwi Sl. 73/1: mimi hill comfort stop; from Maori ‘mimi’, to urinate; eg ‘Coming up to mimi hill, chief?’.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].