circuittop: Bulbs in a series circuit are dim because electricity has to pass through every bulb in the circuit before returning to the battery.bottom: Bulbs in a parallel circuit shine brightly because each bulb has its own circuit that connects directly to the battery.cir·cuit (sûr?k?t)n.1. a. A closed, usually circular line that goes around an object or area. See Synonyms at circumference.b. The region enclosed by such a line.2. a. A path or route the complete traversal of which without local change of direction requires returning to the starting point.b. The act of following such a path or route.c. A journey made on such a path or route.3. Electronics a. A closed path followed or capable of being followed by an electric current.b. A configuration of electrically or electromagnetically connected components or devices.4. a. A regular or accustomed course from place to place; a round: a salesperson on the Detroit-Minneapolis-Chicago circuit; a popular speaker on the lecture circuit.b. The area covered by such a course, especially by the judge or judges of a court.5. a. An association of theaters in which plays, acts, or films move from theater to theater for presentation.b. A group of nightclubs, show halls, or resorts at which entertainers appear in turn.c. A series of competitions held in different places.intr. & tr.v. cir·cuit·ed, cir·cuit·ing, cir·cuits To make a circuit or circuit of.[Middle English, circumference, from Old French, from Latin circuitus, a going around, from past participle of circum?re, to go around : circum-, circum- + ?re, to go; see ei- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.circuit (?s??k?t) n1. a. a complete route or course, esp one that is curved or circular or that lies around an objectb. the area enclosed within such a route2. the act of following such a route: we made three circuits of the course. 3. (Electronics) a. a complete path through which an electric current can flowb. (as modifier): a circuit diagram. 4. a. a periodical journey around an area, as made by judges, salesmen, etcb. the route traversed or places visited on such a journeyc. the persons making such a journey5. (Protestantism) an administrative division of the Methodist Church comprising a number of neighbouring churches6. (Law) English law one of six areas into which England is divided for the administration of justice7. (Theatre) a number of theatres, cinemas, etc, under one management or in which the same film is shown or in which a company of performers plays in turn8. (General Sporting Terms) sport a. a series of tournaments in which the same players regularly take part: the international tennis circuit. b. the circuit the contestants who take part in such a series9. (Motor Racing) chiefly Brit a motor racing track, usually of irregular shapevbto make or travel in a circuit around (something)[C14: from Latin circuitus a going around, from circum?re, from circum around + ?re to go] ?circuital adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014cir?cuit (?s?r k?t) n. 1. an act or instance of going or moving around. 2. a circular journey; round. 3. a roundabout journey or course. 4. a. a periodical journey from place to place, as by judges to hold court, ministers to preach, or salespeople covering a route. b. the persons making such a journey. c. the route followed or district covered. 5. the line bounding any area or object; the distance about an area or object. 6. a. the complete path of an electric current, including the generating apparatus, intervening resistors, or capacitors. b. any well-defined segment of a complete circuit. 7. a means of transmitting communication signals or messages, usu. comprising two channels for interactive communication. 8. a number of theaters, clubs, parks, or the like controlled by one management, devoted to one pursuit, or visited in turn by the same participants. 9. a league or association: a softball circuit. v.t. 10. to go or move around; make the circuit of. v.i. 11. to go or move in a circuit. [1350?1400; Middle English