ghost
n.— «The two are known as “ghosts,” in police parlance, or undercover officers whose job is to keep an eye on and provide back-up to a third undercover officer who is doing the buy-and-bust work.» —“Man Shot Dead by Police on Lafayette” The Local (Fort Greene, Brooklyn, New York) July 11, 2009. (source: Double-Tongued Dictionary)
Further reading
It’s hard to imagine now, but there was a time when people disagreed over the best word to use when answering the phone. Alexander Graham Bell suggested answering with ahoy! but Thomas Edison was partial to hello! A fascinating new book about...
Sue from Bloomsburg, Pennsylvania, wants help regarding a dispute with her husband about terms they use in a pickup sport like softball and you don’t have enough players to field a full-size team. If you get onto second base but then have to...