From HomoExcelsior

1. A plane curve everywhere equidistant from a given fixed point, the center. 2. A planar region bounded by a circle. 3. Something, such as a ring, shaped like such a plane curve. 4. a satellite's circle around the earth. 5. A curved section or tier of seats in a theater. 6. A series or process that finishes at its starting point or continuously repeats itself; a cycle. 7. A group of people sharing an interest, activity, or achievement. 8. A territorial or administrative division, especially of a province, in some European countries. 9. well-known in artistic circles. 10. A vicious circle. 11. To make or form a circle around; enclose. 12. To move in a circle around. 13. To move in a circle.