"Send in the clowns.. There ought to be clowns"

Cirque du Soleil - Toronto

First attested in English 14th century, the word circus derives from Latin circus,^[1] which is the romanization of the Greek κίρκος (kirkos), itself a metathesis of the Homeric Greek κρίκος(krikos), meaning "circle" or "ring".^[2] 

In the book De Spectaculis early Christian writer Tertullian claimed that the first circus games were staged by the goddess Circe in honor of her father Helios, the Sun God. This claim accords well with the fact that many Roman games were indeed dedicated to the Sun God.

.... Wikipedia