Terminology The term octopus, pronounced /ˈɒktəpʊs/, is from Greek ὀκτάπους (oktapous), "eight-footed",[32][33] with plural forms: octopuses /ˈɒktəpʊsɪz/, octopi /ˈɒktəpaɪ/, or octopodes /ɒkˈtɒpədiːz/. Currently, octopuses is the most common form in both the US and the UK; octopodes is rare, and octopi is often objectionable.[34]
The plural form octopi is often described as a hypercorrection. The Oxford English Dictionary (2008 Draft Revision)[35] lists octopuses, octopi and octopodes (in that order); it labels octopodes "rare", although the correct Greek plural form, and notes that octopi derives from the "apprehension" that octōpūs is a second declension Latin noun, though it is not. It is a Latinization of Greek third-declension masculine oktṓpous (ὀκτώπους, 'eight-foot'), plural oktṓpodes (ὀκτώποδες
. If the word were native to Latin, it would be octōpēs, plural octōpedes, after the pattern of pēs ('foot'), plural pedēs, analogous to "centipede".[36] The actual Latin word for octopus and other similar species is polypus, from Greek polýpous (πολύπους, 'many-foot'); usually the inaccurate plural polypī is used instead of polypodēs.
In modern Greek, the word is khtapódi (χταπόδι
, plural khtapódia (χταπόδια
, from Medieval oktapódion (ὀκταπόδιον
, equivalent to Classical oktápous (ὀκτάπους
, variant of oktṓpous.
Chambers 21st Century Dictionary[37] and the Compact Oxford Dictionary[38] list only octopuses, although the latter notes that octopodes is "still occasionally used"; the British National Corpus has 29 instances of octopuses, 11 of octopi and 4 of octopodes. Merriam-Webster 11th Collegiate Dictionary lists octopuses and octopi, in that order; Webster's New World College Dictionary lists octopuses, octopi and octopodes (in that order).
Fowler's Modern English Usage states that "the only acceptable plural in English is octopuses," and that octopi is misconceived and octopodes pedantic.
The term octopod (plural octopods or octopodes) is taken from the taxonomic order Octopoda but has no classical equivalent. The collective form octopus is usually reserved for animals consumed for food.