Aussie slang for Nitrous Oxide, typified by the ringing in the ears commonly experienced after a good solid huff or two.
"Things were kind of dragging until he busted out the nang-nang. Then it was on! We didn't leave that couch for two days."
ayon kay Who the fuck ever ika-11 ng Pebrero, 2010
A moron or person who is prone to doing foolish things.
Gore, you are such a nangnang.
ayon kay Russellnz ika-20 ng Hulyo, 2005