What is a "Picayune"?

picayune |ˌpikiˈyoōn|
adjective informal
petty; worthless : the picayune squabbling of party politicians.
noun
a small coin of little value, esp. a 5-cent piece.
• informal an insignificant person or thing.
ORIGIN early 19th cent.: from French picaillon, denoting a Piedmontese copper coin, also used to mean ‘cash,’ from Provençal picaioun, of unknown ultimate origin.