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

The team evaluated the size of the ancient octopuses using allometric calculation—a method that used the proportional growth rates of modern, long-bodied finned octopuses to extrapolate the size of their extinct relatives. —Jacek Krywko, ArsTechnica, 24 Apr. 2026

So a creature like an octopus — which is made up of almost entirely soft tissue — has been harder to come by in the fossil record. —Ari Daniel, NPR, 24 Apr. 2026

Both species are part of what scientists now believe were enormous, finned octopuses that used paddle-like appendages on their heads to move through ancient oceans. —Ryan Brennan, Kansas City Star, 24 Apr. 2026

The fossils belonged to a group of extinct finned octopuses known as Cirrata that researchers believed crushed their prey with powerful jaws. —Brie Stimson, FOXNews.com, 24 Apr. 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
• pithecanthropus
• 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"