Green’s Dictionary of Slang

(N.Z. prison) urine, thus mimi boy/collector/man/squad/tester, the officer(s) in charge of urine testing, mimi hill/hoihoi a urine sample or test, waka mimi, the van diriven by urine testers.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 117/1: mimi n. urine mimi boy (also mimi collector or mimi man or mimi tester) the prison officer who obtains inmates' urine samples for testing for evidence of drug use. mimi hill a urine test. mimi hoihoi a urine sample, a urine test. [lit. ‘noise of urine’, from Maori mimi = ‘urine’ + hoihoi = ‘noise’.] mimi screw see screw. mimi squad, the the prison officers who obtain inmates' urine samples for testing for evidence of drug use waka mimi the van driven by the people who test inmates' urine samples for evidence of drug use.