According to Merriam-Webster, both octopuses and octopi are acceptable plurals. The reason for the octopi plural is because some people mistakenly associate octopus with Latin words like syllabus and alumnus. However, the word octopus is actually of Greek origin. The plural of octopus in Greek is, in fact, octopodes.

noun. hip·​po·​pot·​a·​mus | / ˌhi-pə-ˈpä-tə-məs / plural hippopotamuses or hippopotami/ ˌhi-​pə-​ˈpä-​tə-​ˌmī , -​(ˌ)mē /

hippos? A bloat. Might seem a little facetious, but that is indeed the term used to describe a collection of these semi-aquatic mammals.

Grammatically speaking, the plural for octopus is octopuses. As the Merriam-Webster dictionary points out, people use three different terms, however: octopi, octopuses, and octopodes. While “octopi” has become popular in modern usage, it’s wrong.

The notion that the plural of “octopus” is “octopi” must arise from the fallacy that “octopus” is a Latin noun of the second declension, like “amicus” (friend) — whose nominative plural really is “amici.” But “octopus” is a Greek noun of the third declension.

The scientific Latin term octopus was derived from Ancient Greek ὀκτώπους, a compound form of ὀκτώ (oktō, “eight”) and πούς (pous, “foot”), itself a variant form of ὀκτάπους, a word used for example by Alexander of Tralles (c. 525–c. 605) for the common octopus.

three hearts

The world “octopus” comes from the Greek, októpus, meaning “eight foot.” The word’s Greek roots means it’s pluralized as a Greek word, too, which depends on both a noun’s gender and the last letter it ends with.

The octopus’s stomach, gills, and some other parts are inside it. The head is much smaller and is located where the octopus’s eyes are. An octopus gets its name from its eight long arms. The octopus is also able to taste with its suckers.