an ancient amphitheater in Rome, begun a.d. c70 by Vespasian, having the form of an oval 617 by 512 feet (188 by 156 meters).
(lowercase) coliseum.
According to tradition, persecuted Christians (see also Christian) were fed to lions in the Colosseum for the entertainment of the Romans. (See also bread and circuses.)
Some of the contests staged in the Colosseum were between gladiators, who fought with swords; some were between people and animals. The arena could even be flooded for mock sea battles.
< Latin, noun use of neuter of colossēus gigantic < Greek kolossiaîos, equivalent to koloss ( ós ) colossus + -iaios adj. suffix
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
“So instead of just needing a ticket for the Colosseum, visitors may increasingly need to plan and secure access to Rome itself in advance during high-demand windows.”
From The Wall Street Journal • May 15, 2026
The conservation group has taken issue with the Colosseum Mine, where workers drilled for gold and silver until the 1990s.
From Los Angeles Times • Apr. 15, 2026
“It’s like the Roman Colosseum, with the roar of the crowd, the thirst for a powerful hit. It is incredibly emblematic of what America is in a lot of different ways.”
From The Wall Street Journal • Feb. 3, 2026
There have certainly been occasions when Select Committee hearings have felt worthy of Rome's Colosseum, with MPs grand-standing and landing blows.
From BBC • Nov. 24, 2025
“Of course, it’s not like the old days. When the Colosseum was first built, you know, they could flood the whole arena. They had sea battles with ships modeled on real ones.”
From "Tiger, Tiger" by Lynne Reid Banks
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
