"The word "polka" comes ultimately from Polish and means "Polish woman." The most common of the stories about the origin of the dance is that a Bohemian peasant girl created the hop-step-close-step dance in the early 1830s. By 1835, it had made its way to Prague, where it was named as a tribute to Polish women - thus the borrowing of the Polish word. At one time some saw "polka" as a corruption of the Czech word "pulka," meaning "half," which recognized the half step in the dance, but our etymologists now reject that theory. At any rate, the polka captured hearts in Paris and London by the 1840s and moved on to the United States. Today's polka, an adaptation of the older form, is a significant part of American folk dancing.

It was common in the 19th century for a craze like the polka to lend its name enthusiastically to fashions, designs, or furnishings that were part of the same culture. Polka hats and polka gauze did not outlast the craze the way the polka dot and polka jacket did.

Conjecture about the dot centers on several possible connections, one being to the dotted rhythm of the dance, another being to the spots where partners placed their feet while dancing. All we can say for certain is that the "polka" of "polka dot" comes from the name of the dance."

http://www.jewishworldreview.com/.../...ry_men080405.php3