I•oˈaɪ oʊ, ˈi oʊ(n.)

1. (in Greek myth) a woman loved by Zeus and changed by him into a heifer, which Hera claimed and put under Argus' guardianship.

   Category: Mythology

2. a large volcanically active moon of Jupiter.

   Category: Astronomy

Io.

1. Iowa.

   Category: Geography (places)

I/O

1. Computers. input/output.

   Category: Computers

I.O.

or i.o.

1. indirect object.

   Category: Grammar