octopus

noun

oc·​to·​pus ˈäk-tə-pəs 

-ˌpu̇s

plural octopuses or octopi ˈäk-tə-ˌpī 

1

plural also octopodes äk-​ˈtä-​pə-​ˌdēz 

-​ˈtō-

: any of a genus (Octopus) of cephalopod mollusks that have eight muscular arms equipped with two rows of suckers

broadly : any octopod excepting the paper nautilus

2

: something that resembles an octopus especially in having many centrally directed branches

… an octopus of a corporation which lends, buys, produces, and sells.

—Atlantic

Illustration of octopus

• octopus 1

The Plurals of Octopus: Usage Guide

The plurals of octopus are octopi, octopuses, and octopodes. Octopi is the oldest, having been adopted in the belief that words of Latin origin should have Latin plural forms. Though octopus did enter English via New Latin, it is in fact ultimately from Greek. For this reason, it was later given the Greek plural octopodes. In between the adoption of these etymology-based plural forms the word also gained a regular English plural: octopuses. This is now the most common plural form, with octopi also seeing some regular use. Octopodes is rare, but all three are accepted.

Examples of octopus in a Sentence

Recent Examples on the Web

Some of my favorites are coming back too, like El Pulpo Magnifico, Duane Flatmo's fire-breathing octopus, and the Monaco, a 40-foot ship with three masts that sails across dust instead of water. — Jim Dobson, Forbes.com, 29 Aug. 2026

Koloski-Ostrow cites one ancient account of an intrepid octopus, which climbed out of a toilet to devour fish stored in the household pantry. — Andrew Coletti, Popular Science, 27 Aug. 2026

This summer, many of the young octopuses made their way into open water off the towns of Cesenatico and Riccione, some of the areas hardest hit by the invasive crab species. — Moná Thomas, PEOPLE, 27 Aug. 2026

Italian scientists have released 130,000 common octopuses (and counting) to fight blue crabs that have proliferated in parts of the Mediterranean, to the detriment of local species. — Gennaro Tomma, Scientific American, 25 Aug. 2026

Word History

Etymology

New Latin Octopod-, Octopus, from Greek oktōpous

First Known Use

1759, in the meaning defined at sense 1

Rhymes for octopus

• blunderbuss
• platypus
• xenopus
• puss

Kids Definition

octopus

noun

oc·​to·​pus ˈäk-tə-pəs 

plural octopuses or octopi -ˌpī 

1

: any of various sea mollusks that are cephalopods having eight muscular arms with two rows of suckers which hold objects (as its prey)

2

: something suggestive of an octopus

especially : a powerful grasping organization with many branches

Etymology

from scientific Latin Octopod-, Octopus "octopus," from Greek oktōpous, literally, "eight-footed," from oktō "eight" and pous "foot"