Noun

(en noun)

A festive occasion marked by parades and sometimes special foods and other entertainment.

*{{quote-magazine, date=2013-06-07, author=David Simpson

, volume=188, issue=26, page=36, magazine=(The Guardian Weekly) , title= Fantasy of navigation , passage=Like most human activities, ballooning has sponsored heroes and hucksters and a good deal in between. For every dedicated scientist patiently recording atmospheric pressure and wind speed while shivering at high altitudes, there is a carnival barker with a bevy of pretty girls willing to dangle from a basket or parachute down to earth.}}

(US English) a traveling amusement park, called a funfair in UK English.

Noun

(es)

A traveling company of performers that may include acrobats, clowns, trained animals, and other novelty acts, that gives shows usually in a circular tent.

The circus will be in town next week.

A round open space in a town or city where multiple streets meet.

Oxford Circus in London is at the north end of Regent Street.

(historical) In the ancient Roman Empire, a building for chariot racing.

(military, World War II) A code name for bomber attacks with fighter escorts in the day time. The attacks were against short-range targets with the intention of occupying enemy fighters and keeping their fighter units in the area concerned.

* RAF Web - Air of Authority

... the squadron (No. 452) moved to Kenley in July 1941 and took part in the usual round of Circus , Rhubarb and Ramrod missions.

(obsolete) Circuit; space; enclosure.

The narrow circus of my dungeon wall. — Byron.