1. [n]  movement once around a course; "he drove an extra lap just for insurance"
2. [n]  a journey or route all the way around a particular place or area; "they took an extended tour of Europe"; "we took a quick circuit of the park"; "a ten-day coach circuit of the island"
3. [n]  an electrical device that provides a path for electrical current to flow
4. [n]  (British) a racetrack for automobile races
5. [n]  (law) a judicial division of a state or the United States (so-called because originally judges traveled and held court in different locations); one of the twelve groups of states in the United States that is covered by a particular circuit court of appeals
6. [n]  an established itinerary of venues or events that a particular group of people travel to; "she's a familiar name on the club circuit"; "on the lecture circuit"; "the judge makes a circuit of the courts in his district"; "the international tennis circuit"
7. [v]  make a circuit; "They were circuiting about the state"

1. \Cir"cuit\, n. [F. circuit, fr. L. circuitus, fr.
   circuire or circumire to go around; circum around + ire to
   go.]
   1. The act of moving or revolving around, or as in a circle
      or orbit; a revolution; as, the periodical circuit of the
      earth round the sun. --Watts.
   
   2. The circumference of, or distance round, any space; the
      measure of a line round an area.
   
            The circuit or compass of Ireland is 1,800 miles.
                                                  --J. Stow.
   
   3. That which encircles anything, as a ring or crown.
   
            The golden circuit on my head.        --Shak.
   
   4. The space inclosed within a circle, or within limits.
   
            A circuit wide inclosed with goodliest trees.
                                                  --Milton.
   
   5. A regular or appointed journeying from place to place in
      the exercise of one's calling, as of a judge, or a
      preacher.
   
   6.
      (a) (Law) A certain division of a state or country,
          established by law for a judge or judges to visit, for
          the administration of justice. --Bouvier.
      (b) (Methodist Church) A district in which an itinerant
          preacher labors.
   
   7. Circumlocution. [Obs.] ``Thou hast used no circuit of
      words.'' --Huloet.
   
   {Circuit court} (Law), a court which sits successively in
      different places in its circuit (see {Circuit}, 6). In the
      United States, the federal circuit courts are commonly
      presided over by a judge of the supreme court, or a
      special circuit judge, together with the judge of the
      district court. They have jurisdiction within statutory
      limits, both in law and equity, in matters of federal
      cognizance. Some of the individual States also have
      circuit courts, which have general statutory jurisdiction
      of the same class, in matters of State cognizance.
   
   {Circuit or Circuity} {of action} (Law), a longer course of
      proceedings than is necessary to attain the object in
      view.
   
   {To make a circuit}, to go around; to go a roundabout way.
   
   {Voltaic or Galvanic} {circuit or circle}, a continous
      electrical communication between the two poles of a
      battery; an arrangement of voltaic elements or couples
      with proper conductors, by which a continuous current of
      electricity is established.
   
   

2. \Cir"cuit\, v. i.
   To move in a circle; to go round; to circulate. [Obs.] --J.
   Philips.
   
   

3. \Cir"cuit\, v. t.
   To travel around. [Obs.] ``Having circuited the air.'' --T.
   Warton.
   
   

1. A communications path in a circuit switching network.

2. A complete path through which an electric current can flow.

The term is used loosely for any device or subsystem using electrical or electronic components. E.g. "That lightning bolt fried the circuits in my GPS receiver". An integrated circuit (IC) contains components built on a Silicon die.

the apparent diurnal revolution of the sun round the earth (Ps. 19:6), and the changes of the wind (Eccl. 1:6). In Job 22:14, "in the circuit of heaven" (R.V. marg., "on the vault of heaven") means the "arch of heaven," which seems to be bent over our heads.