1. 1. A public entertainment consisting typically of a variety of performances by acrobats, clowns, and trained animals.
   2. A traveling company that performs such entertainments.
   3. A circular arena, surrounded by tiers of seats and often covered by a tent, in which such shows are performed.
2. A roofless oval enclosure surrounded by tiers of seats that was used in antiquity for public spectacles.
3. Chiefly British. An open circular place where several streets intersect.
4. Informal. Something suggestive of a circus, as in frenetic activity or noisy disorder: "The city is a circus of the senses" (William H. Gass).

[Middle English, round arena, from Latin, circus, circle. See circle.]

WORD HISTORY   The modern circus owes its name, but fortunately not its regular program of events, to the amusements of ancient times. The Latin word circus, which comes from the Greek word kirkos, "circle, ring," referred to a circular or oval area enclosed by rows of seats for spectators. In the center ring, so to speak, was held a variety of events, including chariot races and gladiatorial combats, spectacles in which bloodshed and brutality were not uncommon. The first use of circus recorded in English, in a work by Chaucer written around 1380, probably refers to the Circus Maximus in Rome. Our modern circus, which dates to the end of the 18th century, was originally an equestrian spectacle as well, but the trick riders were soon joined in the ring by such performers as ropedancers, acrobats, and jugglers. Even though the circular shape of the arena and the equestrian nature of some of the performances are carried over from its Roman namesake, the modern circus has little connection with its brutal namesake of long ago.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.