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
Asthenosphere, a geologist’s term for the molten layer beneath the earth’s crust, sparks a journey that stretches all the way from ancient Greece to the author of Uncle Tom’s Cabin. Plus: What the heck is a dogberg? It’s when...
There was a time when William Shakespeare was just another little seven-year-old in school. Classes in his day were demanding — and all in Latin. A new book argues that this rigorous curriculum actually nurtured the creativity that later flourished...