Io

Io

Noun (Proper) · /ˈaɪ.əʊ/

Definition

The innermost of Jupiter's four large Galilean moons, notable for intense volcanic activity; in Greek mythology, a priestess of Hera transformed into a heifer by Zeus; in computing, an abbreviation for Input/Output.

Origin

From Greek Io, a figure in Greek mythology. The moon was named by Simon Marius (though Galileo discovered it) after the mythological figure. The I/O abbreviation emerged with early computing in the mid-20th century.