prob. < obs. simon, a dollar, by assoc. with napoleon
simoleon in American English
(səˈmouliən)
noun
slang
a dollar
Word origin
[1895–1900, Amer.; orig. uncert.]This word is first recorded in the period 1895–1900. Other words that entered Englishat around the same time include: apothecaries' measure, backwind, calling card, freewheel, neon