Actually, the word "dollar" comes from the word "thaler". In old Bohemia, now part of the Czech Republic, silver mines allowed the minting of "thalers" which soon became renowned for their weight and purity. They were known as "Joachimsthalers". The thalers became so widespread that Austria minted the "Maria Theresa Thaler" (David Merrill's avatar is based on it); and in some tribal communities restruck MTTs are still used as money.

The word came to us via the Spanish 8 Reales coin, which like the MTT was trusted for its weight and purity. This coin was known as the Spanish Milled Dollar, which to remedy a lack of small change was sometimes cut into 8 "bits" -- thus, "two bits" were a quarter of a dollar.