1. Of little or small importance.
2. Petty; small-minded.
1. Something of little value; a trifle.
2. A half-real (an old Spanish coin).
3. Any U.S. coin of small value, such as a nickel.
Etymology: French picaillon, small coin
The New Orleans Times-Picayune does not print picayune stories;
it received its name from the fact that its original price (in the mid-1800s) was one picayune.
And of course, there's the Bloom Picayune.