Circle
(Cir"cle) n. [OE. cercle, F. cercle, fr. L. circulus (Whence also AS. circul), dim. of circus circle,
akin to Gr. kri`kos, ki`rkos, circle, ring. Cf. Circus, Circum-.]
1. A plane figure, bounded by a single curve line called its circumference, every part of which is equally
distant from a point within it, called the center.
2. The line that bounds such a figure; a circumference; a ring.
3. (Astron.) An instrument of observation, the graduated limb of which consists of an entire circle.
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) 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.
10. Indirect form of words; circumlocution. [R.]
Has he given the lie,
In circle, or oblique, or semicircle.
J. Fletcher.
11. A territorial division or district.
The Circles of the Holy Roman Empire, ten in number, were those principalities or provinces which
had seats in the German Diet.
Azimuth circle. See under Azimuth. — Circle of altitude (Astron.), a circle parallel to the horizon,
having its pole in the zenith; an almucantar. — Circle of curvature. See Osculating circle of a curve
— Circle of declination. See under Declination. — Circle of latitude. (a) (Astron.) A great circle
perpendicular to the plane of the ecliptic, passing through its poles. (b) (Spherical Projection) A small
circle of the sphere whose plane is perpendicular to the axis. — Circles of longitude, lesser circles
parallel to the ecliptic, diminishing as they recede from it. — Circle of perpetual apparition, at any
given place, the boundary of that space around the elevated pole, within which the stars never set. Its
distance from the pole is equal to the latitude of the place. — Circle of perpetual occultation, at any
