Here are a few of my favorite entries, all beginning with the letter “D,” from Word and Phrase Origins, a delightful book published in 1997.
Dear. Dear is related to the word dearth, meaning scarcity. Over the years, dear came to mean expensive, because the cost of something scarce is driven up by the law of supply and demand.
Deep-six. An old nautical term, deep-six originally meant to drown (the six meaning six fathoms down). It now conveys that something once active has been killed: "That project was going nowhere, it's good that we deep-sixed it."
Donkey's years. Donkey's years means a very long time. First recorded in 1916, it's a play on donkey's ears, which means the same thing (referring to the disproportionately long ears of a donkey).
Draw a blank. Now meaning not being able to recall something, draw a blank is a reference to lotteries in the late 19th century in which people bought numbered tickets to win prizes; drawing a blank ticket meant you won nothing.
Dubok. Often uses in spy novels, dubok is a synonym for a safe place where espionage activities can be carried out. It comes from the Russian word for oak tree.
A note about the author: Word and Phrase Origins was written by Robert Hendrickson, now 85 years old and the author of more than 25 other books, including American Literary Anecdotes, New York Tawk, and More Cunning than Man: A Social History of Rats and Men.