What’s The Plural of Syllabus? Syllabuses vs. Syllabi

teacher in classroom

You’re back in class and your instructors have just handed out the… course outlines. Should you call them syllabuses? Or syllabi?

In this article, we’ll break down the difference between the words syllabuses and syllabi, explain why there’s two options, and even get into why the word syllabus is likely based on a misunderstanding of an earlier word.

Quick summary

Both syllabuses and syllabi are acceptable and commonly used plurals of syllabus.

Is it syllabuses or syllabi?

A syllabus is the outline of a course that you get at the beginning of it. The word sounds very official and academic, but it’s actually probably based on a misunderstanding.

Syllabus derives from New Latin, probably from a misreading—in manuscripts of the Roman writer Cicero—of the Greek síttybās, which is a plural form of the word referring to a label on a papyrus roll (such as one specifying its title and author).

Syllabus is an example of the class of Latin words that end in -us and get pluralized by replacing -us with -i. Many English words with strong roots in Latin have retained this pluralization pattern, including alumnus/alumni and stimulus/stimuli.

In the case of syllabus, both syllabi and the regular plural syllabuses are commonly used.

There are a few other cases of Latin-derived terms in which both endings are used, most famously octopuses/octopi, but also platypuses/platypi, cactuses/cacti, and thesauruses/thesauri.

Still, in all these cases, it’s more common to pluralize with a plain old -es. But that doesn’t mean either one is wrong—nor is one “more correct.” Both syllabuses and syllabi are perfectly acceptable.

Maybe the best choice is to use the term your professor uses. Or you can opt to avoid the issue altogether by simply calling them course outlines.

Get the whole story about the octopuses vs. octopi debate.

Previous "Maki" Time To Learn The History Of These Sushi Names Next Gage vs. Gauge: What's The Difference?