1. (initialism) .  (computing, electronics) input and output.
  2. (initialism) .  (grammar) Indirect Object.
  3. (initialism) .  (emergency medicine) intraosseous.
  4. Proper noun.  (mythology) The daughter of Inachus.
  5. Proper noun.  (astronomy) A moon of Jupiter, known for its volcanic activity, peppered with about 400 active volcanoes.
  6. Noun.  A type of moth, the io moth.

This is an unmodified, but possibly outdated, definition from Wiktionary and used here under the Creative Commons license. Wiktionary is a great resource. If you like it too, please donate to Wikimedia.

This entry was last updated on RefTopia from its source on 3/20/2012.