Judas window
n.— «Classroom surveillance is nothing new. Most classroom doors have a glass section—a Judas window in chalkie parlance—allowing management to surreptitiously spy on Sir’s lesson.» —“Yes, head boys must have the latest toys” by Hugh Reilly Scotsman (Glasgow, Scotland) Mar. 9, 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...