A picayune was a Spanishcoin, worth half a real. Its name derives from the Frenchpicaillon, which is itself from the Provençalpicaioun, meaning "small coin". By extension, picayune can mean "trivial" or "of little value".
Aside from being used in Spanish territories, the picayune and other Spanish currency was used throughout the colonial U.S.. Spanish dollars were made legal tender in the United States by an act on February 9, 1793, until it was demonetized on February 21, 1857. The coin's name first appeared in Florida and Louisiana where its value was worth approximately six and a quarter cents, and whose name was sometimes used in place of the U.S. nickel.