Words at Play : A Wealth of Words
Definition:
: a dollar
Example:
"When [Ty Cobb] came to bat in the first inning, a little lass from Georgia, Miss Mary Brennan, walked out to the plate and presented Ty with a bunch of posies and a leather bill folder with gold edges. In the folder was one buck, or simoleon, or washer; you know, a dollar."
May 12, 1919, The New York Times
About the Word:
The origins of this word, which first appeared in the late 19th century, are murky, though it may have been created as a play on napoleon, a now-extinct French coin that was worth 20 francs.
Simoleon has gotten a bit more life recently as a result of "The Sims" video game series, in which the unit of currency is "simoleons."