(rare) An exclamation of joy or triumph.

(Greek mythology) The daughter of Inachus river god, and a lover of Zeus, turned by the latter into a heifer.

A type of moth, the io moth.

(computing, electronics) Initialism of input and output. / (grammar) Initialism of indirect object. / Initialism of intelligence officer.

(emergency medicine) Abbreviation of intraosseous.

(pharmacology) Used to form names of iodine-containing contrast media.

An island in the Cyclades, Greece.

plural of io

(computing, mobile telephony) A mobile operating system (OS) created and developed by Apple Inc. exclusively for its hardware.

plural of IO