Plural of Prius, Prii? Not According to Latin Experts


CARS.COM — Ever wonder what the plural is for the Toyota Prius? It’s been something of a gray area to our copy editors, and now that there’s a Prius v, a plural word for the vehicle could come in handy.

Related: More Toyota Prius News

Before we could make up our minds, Toyota decided today that the plural form is “Prii” (pronounced PREE-eye). That decision was the result of a marketing campaign in which Toyota asked the public about the plural possibilities: “Prius,” “Priuses,” “Prii,” “Priem,” or “Pri.”

“Prii” received 25%. “Prius” came in a close second with 24%.

We think Toyota is getting a little meta on this one. We’ve certainly heard the Latin-inspired “Prii” bounced around among auto journalists before today, in a cheeky manner of course. But Prii is no longer just a flippant expression; it’s a real word, at least according to Other dictionaries, such as Merriam-Webster and the Oxford English Dictionary, don’t contain an entry.

The original meaning for the singular “Prius” originates from a 19th-century adjective referring to “prior.” There’s an even older noun derivative from the 15th century, according to the Oxford English Dictionary.

Nick Young, a Latin and classical language studies instructor at the University of Detroit Mercy, told the Detroit Free Press that the plural of “Prius” is actually “Priora” or “Priores.” What’s the difference? Like many languages, Latin assigns gender to nouns. “Priores” is the feminine plural, while “Priora” would be the neuter plural form.   

Ben Zimmer, a columnist for The New York Times, counters that either “Priora” or “Prii” are correct answers, but he told the Free Press that adding Latin plurals to “Prius” seems a bit forced. “We’re not speaking Latin. We might as well form the word the way English plurals are formed,” Zimmer said.

In that case, the English plural really should be “Priuses,” even if it sounds a bit silly. And it skirts the issue of whether cars should be described as masculine, feminine, or neuter nouns — a good outcome not just for Toyota’s hybrid but for machines (and people) everywhere.’s Editorial department is your source for automotive news and reviews. In line with’s long-standing ethics policy, editors and reviewers don’t accept gifts or free trips from automakers. The Editorial department is independent of’s advertising, sales and sponsored content departments.

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