from The Century Dictionary.

  • noun In mythology, a daughter of Inachus, metamorphosed into a heifer and caused to be tormented by a terrible gadfly by Hera, in jealous revenge for the favors of Zeus. See Argus, 1.
  • noun The innermost of the four satellites of Jupiter.
  • noun In entomology: A genus of vanessoid butterflies.
  • noun [lowercase] The peacock butterfly, Vanessa io: used both as the technical specific name and as an English word.
  • noun [lowercase] A showy and beautiful moth of North America, Hyperchiria io, or Saturnia io, of yellow coloration, with prominent pink and bluish eyes on the hinder wings.
  • noun An abbreviation of Iowa.
  • A Latin interjection, or exclamation of joy or triumph: sometimes used as a noun in English.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • interjection An exclamation of joy or triumph.
  • noun A type of moth, the io moth.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun the closest of Jupiter's moons; has active volcanoes
  • noun (Greek mythology) a maiden seduced by Zeus; when Hera was about to discover them together Zeus turned her into a white heifer


from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin; compare Ancient Greek ἰώ (iō, "oh!").

from Wiktionary, Creative Commons Attribution/Share-Alike License

Modern Latin, from Ancient Greek ἰώ (iṓ, "Io").


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  • Obsolete name for the Hawaiian Hawk.

    December 7, 2007

  • The io moth of North America (OED2); a cry of joy (SOWPODS); Hawaiian Hawk (not obsolete) (MW3).

    December 8, 2007