3. (Astron.)
Defn: An instrument of observation, the graduated limb of which consists of an entire circle.
Note: When it is fixed to a wall in an observatory, it is called a mural circle; when mounted with a telescope on an axis and in Y's, in the plane of the meridian, a meridian or transit circle; when involving the principle of reflection, like the sextant, a reflecting circle; and when that of repeating an angle several times continuously along the graduated limb, a repeating circle.
4. A round body; a sphere; an orb. It is he that sitteth upon the circle of the earth. Is. xi. 22.
5. Compass; circuit; inclosure. In the circle of this forest. Shak.
6. A company assembled, or conceived to assemble, about a central point of interest, or bound by a common tie; a class or division of society; a coterie; a set. As his name gradually became known, the circle of his acquaintance widened. Macaulay.
7. A circular group of persons; a ring.
8. A series ending where it begins, and repeating itself. Thus in a circle runs the peasant's pain. Dryden.
9. (Logic)
Defn: A form of argument in which two or more unproved statements are used to prove each other; inconclusive reasoning. That heavy bodies descend by gravity; and, again, that gravity is a quality whereby a heavy body descends, is an impertinent circle and teaches nothing. Glanvill.