1. In the form of a circle; round; circumscribed by a circle; spherical; as, the sun appears to be circular
2. Successive in order; always returning.
3. Vulgar; mean; circumforaneous; as a circular poet.
4. Ending in itself; used of a paralogism, where the second proposition at once proves the first, and is proved by it.
5. Addressed to a circle, or to a number of persons having a common interest; as a circular letter.
6. circular lines, such straight lines as are divided from the divisions made in the arch of a circle; as the lines of sines, tangents and secants, on the plain scale and sector.
7. circular numbers, are those whose powers terminate in the roots themselves; as 5 and 6, whose squares are 25 and 36.
8. circular sailing, is the method of sailing by the arch of a great circle.
CIRCULAR, noun A circular letter, or paper.