1553, from Low Ger.
daler, from Ger.
taler (1540, later
thaler), abbrev. of
Joachimstaler, lit. "(gulden) of Joachimstal," coin minted 1519 from silver from mine opened 1516 near
Joachimstal, town in Erzgebirge Mountains in northwest Bohemia. Ger.
Tal is cognate with Eng.
dale. Ger.
thaler was a large silver coin of varying value in the Ger. states (and a unit of the Ger. monetary union of 1857-73 equal to three marks); it was also a currency unit in Denmark and Sweden. Eng. colonists in America used the word in ref. to Spanish pieces of eight. Continental Congress July 6, 1785, adopted
dollar when it set up U.S. currency, on suggestion of Gouverneur Morris and Thomas Jefferson, because the term was widely known but not British. But none were actually used until 1794. The dollar sign ($) is said to derive from the image of the Pillars of Hercules, stamped with a scroll, on the Spanish piece of eight. Phrase
dollars to doughnuts attested from 1890;
dollar diplomacy is from 1910.
[dol-er] 
