Pronunciation: (sûr'kyu-lur), [key]
1. having the form of a circle; round: a circular tower.
2. of or pertaining to a circle: a circular plane.
3. moving in or forming a circle or a circuit: the circular rotation of the earth.
4. moving or occurring in a cycle or round: the circular succession of the seasons.
5. roundabout; indirect; circuitous: a circular route.
6. Logic.of or pertaining to reasoning in which the conclusion is ostensibly proved, but in actuality it or its equivalent has been assumed as a premise.
7. pertaining to a circle or set of persons.
8. (of a letter, memorandum, etc.) addressed to a number of persons or intended for general circulation.
a letter, advertisement, notice, or statement for circulation among the general public.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.