Here are a few of my favorite entries, all beginning with the letter “F," from Word and Phrase Origins, a thoroughly delightful book published in 1997.
Fast shuffle. A fast shuffle by a crooked cardplayer often results in a deck stacked to that player's advantage. Over time, the expression has come to mean a dishonest dealing in any enterprise.
February. February is named for Februria, the name Juno was given as the goddess of fertility. February originally had 29 days, but the Romans took one away and gave it to July, so that July (named after Julius Caesar) wouldn't be inferior to August (named after Augustus Caesar).
Ferris wheel. Introduced at the 1893 World's Colombian Exposition in Chicago, the ride was the work of an Illinois railroad and bridge designer named George Ferris. Weighing over 1,200 tons, the giant steel structure stood 140 feet high and was 250 feet across, with 36 cars capable of carrying 1,400 riders.
Fiddler crab. A tiny crab of the genus Uca, the fiddler crab is so named because it moves its big claw rapidly, the way a fiddler moves his arm.
Fleabitten. It's a color as well as a condition, having been used since the late 16th century to describe a dog, horse, or other animal with a light coat flecked with red; the reddish flecks being reminiscent of the bites of fleas on human skin.
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.