6 English Words with Incognito Latin Origins

Colosseum (or is that coliseum?), arena, circus, muscle, cloaca, and companion have Latin origins that may surprise you!

Bonnie Mills, Writing for
4-minute read
Episode #529

4. Muscle

You may have been surprised that the word circus has origins in the history of chariot races and its round venue. Get ready to be more surprised as we switch gears to discuss two words related to anatomy.

First up is the word muscle. It would make perfect sense if the root of this had something to do with strength. But no. Try the Latin word for “mouse,” which is mus, and its diminutive, musculus, which means “little mouse.” According to the blog Anatomy Words, “the Romans thought that a muscle looked like a mouse running under the skin.” That disturbing image is a stretch, though it is probably easier to see the connection if you're a small woman with little baby muscles. Also related to the Latin word musculus is the English word mussel, that tasty mollusk. The anatomy blog informs us that some species “have the shape of a mouse ear.”

5. Cloaca

Anyone who takes biology is familiar with our next word, which might be a little icky but has interesting origins nevertheless: cloaca. When dissecting a frog in class, you may be tasked with labeling features of its urogenital system. One such spot is the cloaca, which is “where sperm, eggs, urine, and feces exit.” Cloaca comes from the Latin word for “sewer” or “canal.”

Old Roman sewers exist even today, most notably the Cloaca Maxima, which means “greatest sewer.” It was built as a canal in the sixth century BCE. Four hundred years later it was covered over, becoming an underground structure. According to a web site all about ancient history, the Cloaca Maxima is visible today “at the eastern stairs of the Basilica Julia at the Roman Forum, where a door leads to the sewer. Here, you can sometimes hear (and smell) the water in the ancient sewer.”

There are many fascinating ruins to visit in Rome. If you go there with a companion, don't inhale if you're near the Cloaca Maxima! 

6. Companion

We won't end this episode with a discussion of sewers, however. Let's finish up on a more palatable note. Let's think about yummy bread. The word companion comes from a combination of the Latin root com, which means “with,” and the word panis, which means “bread.”


1. Robinson, Lorna. Cave Canem: A Miscellany of Latin Words & Phrases. London: Elwin Street Productions, 2008, p. 63.

2. Shelton, Jo Ann. As the Romans Did: A Sourcebook in Roman Social History. New York: Oxford University Press, 1988, p. 317. 

3. Robinson, Lorna. Cave Canem: A Miscellany of Latin Words & Phrases. London: Elwin Street Productions, 2008, p. 59.

That segment was written by Bonnie Mills, with research help from her teenage son, Jake Trenga.

Image courtesy of Shutterstock.


About the Author

Bonnie Mills, Writing for Grammar Girl

Bonnie Mills has been a copyeditor since 1996.