What does octopi mean?
Octopi is a plural noun meaning several octopuses: soft-bodied marine mollusks in the cephalopod class, each with eight arms. The plural is a Latinized formation from octopus and is fully accepted, although octopuses is generally the more conventional alternative in careful prose. In descriptions of marine biology, aquariums, and the ocean, octopi can refer collectively to these animals without suggesting that they live or move as a group. Octopuses are notable for their intelligence, problem-solving behavior, and ability to change color, giving the plural strong associations with marine life. The word's distinctive ending also makes it memorable, though grammatical context must make the number clear. Because both octopuses and octopi are standard, writers may choose between them according to style and context rather than correctness.
noun (plural)Octopi is the plural of octopus, referring to two or more eight-armed marine mollusks of the class Cephalopoda.
- The plural form of octopus, denoting two or more of these eight-armed cephalopod mollusks.
"The reef was alive with octopi hiding among the rocks."
"The reef was alive with octopi hiding among the rocks."
"Marine biologists used the octopi in the study to compare learning behavior."
Octopi is an accepted plural of octopus. The alternative plural octopuses is also standard and may be preferred in conservative or formal contexts.
"The octopi changed color as the divers approached."
Three hearts, eight arms, and the singular of one of the ocean's most graceful performers: octopus.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does octopi come from?
Octopi is the Latinized plural of octopus. The word octopus comes through Latin from Greek oktōpous, meaning "eight-footed," from oktō ("eight") and pous or podos ("foot"). The same Greek root underlies related English forms such as octopod, octopodes, and octopodal.
Related word forms
How octopi is actually used
Both octopi and octopuses are accepted plurals. Octopuses is generally preferred in more conservative prose, while octopi remains common in zoological, scientific, and informal contexts.
Easily confused with octopi
Octopus is the singular noun, while octopi is one of its accepted plural forms.