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.
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.
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.
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.
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 enterners 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, fromOld French, fromLatincircuitus, a going around, frompast participle ofcircumīre, to go around : circum-, circum- + īre, to go; see ei- in the Appendix of Indo-European roots.]
(click for a larger image)circuit
top: 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.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.