A lexicographer compiles data on the origins and meanings of a treasury of more than four hundred curious sayings and expressions, from "letting the cat out of

Traces the sources of over four hundred expressions and sayings used in everyday speech.

He's as mad as a hatter! Whether it's like a bump on a log or a bat out of hell, these expressions have been around forever, but we've never really known why ..

A Potpourri of curious words like butterscotch, sputnik, or pin money, with explanations of their origin and significance.