dol·lar 
(dŏlər)
(dŏlər)n.
1. See Table at currency.
2. A coin or note that is worth one dollar.
3. Any of various historical silver coins similar to the taler, such as a piece of eight.
4. Money spent or available to be spent: boardwalk shops competing for the tourist dollar.
[Low German daler, taler, from German Taler, short for Joachimstaler, after Joachimstal (Jáchymov), a town of northwest Czech Republic where similar coins were first minted.]