nos
n.— «Taking sly hits of nitrous oxide, or “nos” as it is known on the street, was once a fairly common practice among anaesthetists for whom it was a tool of the trade, Sharpe says.» —“Doctor rubbishes safe ‘nos’ claim” by Greg Meylan Stuff (New Zealand) Apr. 24, 2005. (source: Double-Tongued Dictionary)
Further reading
Cat hair may be something you brush off, but cat hair is also a slang term that means “money.” In the same way, cat beer isn’t alcoholic — some people use cat beer as a joking term for “milk.” And imagine walking on a...
There are eight major planets, but more than a million minor ones, including asteroids. If you discover one, you get the honor of naming it. The Dictionary of Minor Planet Names includes minor planets named for rock bands, jazz musicians, poets, and...