dime Origin: 1786 Fom Answers.com A year before the Constitutional Convention determined what kind of government we wanted for the United States of America, we had already made up our mind about our money: dollars and dimes. On August 8, 1786, an ordinance of the Continental Congress called for "Mills, Cents, Dimes, Dollars," with dime explained as "the lowest silver coin, ten of which shall be equal to the dollar." Thomas Jefferson has been credited with proposing the names for the coins of the new nation. Among them was disme, based on the French word for "tenth," dixième. He suggested that disme be pronounced as if it were spelled deem. But the s was dropped by Congress, and the adopted spelling dime suggested pronunciation in keeping with time and rime. Here's another slightly different but similar article. http://www.bellaonline.com/articles/art30725.asp
The word "dime" is an anglicized version of the word "disme" (pronounced "deem"), meaning tenth. The word is traced back to Simon Stevin van Brugghe, aka Simon Stevinus, aka Stevin. Stevinus invented the decimal system as a convenient alternative to the fractional system that was being used in mathematics. He published a paper, called 'De Thiende' in 1585 under the name Stevin. It was immediately translated to French, and was translated to English by Robert Norton in 1608, and entitled 'Disme: the art of tenths, or, Decimall arithmeticke.' Although the decimal system won a fair amount of acceptance in the scientific community it did nothing for currency. Stevin's paper was republished in 1634. The article found favor in the American Colonies, and when the United States won its independence, the founding fathers, saw the decimal system monetarily as a way to make a dramatic change from the past. Among the first coins issued by the United States was the 1792 Half Disme, and the 1792 Disme. Within a couple of years, the word became "dime."
It remained disme in official government records until 1837. Trivia: The US was the third country to adopt the decimal system for their coinage. Russia was first in 1710, then Sierra Leone in 1791. We adopted it in 1792.