<math>\$</math>
The Tempest, Act II, Scene 1 (Shakespeare)
Gonzalo: "When every grief is entertain'd that's offer'd, Comes to th' entertainer -
Sebastian: "A dollar."
Gonzalo: "Dolour comes to him, indeed: you have spoken truer than you purpos'd."
The last remark by Gonzalo was, of course, a pun since "dolour" is an old-fashioned word for pain or grief, like the modern Spanish word dolor, which also means pain.
The word dollar is much older than the American unit of currency. It is an Anglicised form of "thaler", (pronounced taler, with a long "a"), the name given to coins first minted in 1519 from locally mined silver in Joachimsthal in Bohemia. (Today the town of Joachimsthal lies within the borders of the Czech republic and its Czech name is Jáchymov). Thaler is a shortened form of the term by which the coin was originally known - Joachimsthaler.
The Word "Dollar" and the Dollar Sign $
Professor Cajori contends that the dollar sign is an abbreviation for "pesos." Bear in mind that the Spanish dollar, also known as the peso de 8 reales, was the principal coin in circulation in the U.S. up until 1794, when we began minting our own dollars. In handwriting, "pesos" was usually abbreviated lowercase "ps," with S above and to the right of the P and with the hook on the latter written with one or two deep strokes. As time went on, the P and the S tended to get mashed together and the result was $.