airmail
n.— «Arriving officers were pelted with debris from the rooftops. The “airmail,” as the practice is known among police, stopped only after NYPD helicopters were called in and chased off the assailants with spotlights.» —“At least 10 people shot in lead-up to parade” by Sean Gardiner Newsday (Long Island, N.Y.) Sept. 5, 2005. (source: Double-Tongued Dictionary)
Further reading
What if, instead of being an inanimate object, a dictionary were alive? That’s the idea behind a lavishly illustrated new children’s book called The Dictionary Story (Bookshop|Amazon) by Oliver Jeffers and Sam Winston. This is part of a...
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...