Webster's 1913 Dictionary
IO
I "o, n.; pl. Ios. Etym: [L.; cf. Gr. "iw `.]
Defn: An exclamation of joy or triumph; -- often interjectional.
New American Oxford Dictionary
Io
I o |ˈī -ō, ˈē -ō ˈaɪoʊ | 1 Greek Mythology a priestess of Hera who was loved by Zeus. Trying to protect her from the jealousy of Hera, Zeus turned Io into a heifer. Hera sent a gadfly to torture the heifer, which then fled across the world and finally reached Egypt, where Zeus turned her back into human form. 2 Astronomy one of the Galilean moons of Jupiter, the fifth closest satellite to the planet. It is actively volcanic, colored red and yellow with sulfur compounds, and has a diameter of 2,526 miles (3,630 km ).
Oxford Dictionary
Io
Io |ˈʌɪəʊ | 1 Greek Mythology a priestess of Hera who was loved by Zeus. Trying to protect her from the jealousy of Hera, Zeus turned Io into a heifer. Hera sent a gadfly to torture the heifer, which then fled across the world and finally reached Egypt, where Zeus turned her back into human form. 2 Astronomy one of the Galilean moons of Jupiter, the fifth-closest satellite to the planet, being actively volcanic and coloured red and yellow with sulphur compounds (diameter 3,630 km ).
Sanseido Dictionary
IO
IO 〖 British Indian Territory 〗イギリス領インド洋地域 。ISO の国 地域コードの一 。