Green’s Dictionary of Slang

(N.Z.) a male ‘game’ in which a victim’s trousers and underpants are removed and his genitals blackened with Nugget black shoe polish.

1981		G. Johnston Fish Factory 167: Danny had got a bit stroppy for a while when some of the jokers had tried to nugget his knackers.
1988		McGill Dict. of Kiwi Sl. 77/2: nuggeting unpleasant male party habit of removing victim’s trousers and underpants and applying Nugget shoe polish to testicles; eg ’Let’s get him pissed then give him a good nuggeting. Show the stuck-up prick we don’t need his hoitytoity ways round here. Whadya say?’.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].