polka dot

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One of a number of dots or round spots forming a pattern, as on cloth.
2. n. A pattern or fabric with such dots.

Wiktionary

1. n. Any of a number of uniform round dots, repeated to make a regular geometric pattern on a fabric

WordNet 3.0

1. n. design consisting of a pattern of regularly spaced circular spots