(from κατά and ῥοῦσ, I run), in antiquity, a stretched sloping rope in the theatres, down which the funambuli walked to show their skill.

Some have taken the word to signify the hippodrome or decuriorum wherein the Roman knights used to exercise themselves in running and fighting on horseback. But the most natural meaning is that of a rope fastened at one end to the top of the theatre, and at the other to the bottom, to walk or run down, which was the highest glory of the ancient schenobates or funambuli. Elephants were also taught to run down the catadromus. Suetonius speaks of the exploit of a Roman knight, who passed down the catadromus mounted on an elephant's back.