circle

—circler, n.

/serr"keuhl/, n., v., circled, circling.

n.

1. a closed plane curve consisting of all points at a given distance from a point within it called the center. Equation: x² + y² = r².

2. the portion of a plane bounded by such a curve.

3. any circular or ringlike object, formation, or arrangement: a circle of dancers.

4. a ring, circlet, or crown.

5. the ring of a circus.

6. a section of seats in a theater: dress circle.

7. the area within which something acts, exerts influence, etc.; realm; sphere: A politician has a wide circle of influence.

8. a series ending where it began, esp. when perpetually repeated; cycle: the circle of the year.

9. Logic. an argument ostensibly proving a conclusion but actually assuming the conclusion or its equivalent as a premise; vicious circle.

10. a complete series forming a connected whole; cycle: the circle of the sciences.

11. a number of persons bound by a common tie; coterie: a literary circle; a family circle.

12. Govt. an administrative division, esp. of a province.

13. Geog. a parallel of latitude.

14. Astron.

a. (formerly) the orbit of a heavenly body.

b. See meridian circle.

15. Survey. a glass or metal disk mounted concentrically with the spindle of a theodolite or level and graduated so that the angle at which the alidade is set may be read.

16. a sphere or orb: the circle of the earth.

17. a ring of light in the sky; halo.

v.t.

18. to enclose in a circle; surround; encircle: Circle the correct answer on the exam paper. The enemy circled the hill.

19. to move in a circle or circuit around; rotate or revolve around: He circled the house cautiously.

20. to change course so as to pass by or avoid collision with; bypass; evade: The ship carefully circled the iceberg.

21. circle the wagons,

a. (in the early U.S. West) to form the wagons of a covered-wagon train into a circle for defensive purposes, as against Indian attack.

b. Slang. to prepare for an all-out, unaided defensive fight: The company has circled the wagons since its market share began to decline.

v.i.

22. to move in a circle or circuit: The plane circled for half an hour before landing.

23. Motion Pictures, Television. to iris (usually fol. by in or out).

[bef. 1000; < L circulus, equiv. to circ(us) (see CIRCUS) + -ulus -ULE; r. ME cercle < OF < L, as above; r. OE circul < L, as above]

Syn. 3. ring, halo, corona. 11. CIRCLE, CLUB, COTERIE, SET, SOCIETY are terms applied to restricted social groups. A CIRCLE may be a little group; in the plural it often suggests a whole section of society interested in one mode of life, occupation, etc.: a sewing circle; a language circle; in theatrical circles. CLUB implies an association with definite requirements for membership and fixed dues: an athletic club. COTERIE suggests a little group closely and intimately associated because of congeniality: a literary coterie.

SET refers to a number of persons of similar background, interests, etc., somewhat like a CLIQUE (See ring¹) but without disapproving connotations; however, it often implies wealth or interest in social activities: the country club set. A SOCIETY is a group associated to further common interests of a cultural or practical kind: a Humane Society.

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I

Geometrical curve, one of the conic sections, consisting of the set of all points the same distance (the radius) from a given point (the centre).

A line connecting any two points on a circle is called a chord, and a chord passing through the centre is called a diameter. The distance around a circle (the circumference) equals the length of a diameter multiplied by π (see pi). The area of a circle is the square of the radius multiplied by π. An arc consists of any part of a circle encompassed by an angle with its vertex at the centre (central angle). Its length is in the same proportion to the circumference as the central angle is to a full revolution.

II

(as used in expressions)

Antarctic Circle

Arctic Circle

Cartesian circle

Vienna Circle

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