one-armed bandit
n.— «“One-armed bandits” is another name for fiddler crabs, and “butterballs” are better known as mole crabs or sand fleas.» —“Anglers don’t have to be in a pinch to use crabs” by Mike Marsh News & Observer (Raleigh, N.C.) Oct. 27, 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...