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  • io
    io
    noun
    a small, solitary hawk, Buteo solitarius, having two plumage phases and breeding only on the Island of Hawaii, where it is a rare species and the only indigenous bird of prey: classified as near threatened.
  • Io
    Io
    noun
    a woman who, being loved by Zeus, was transformed into a white heifer and was, at the wish of Hera, first guarded by Argus and later pursued through the world by a gadfly until she reached Egypt, where she resumed her true shape: identified by the Egyptians with Isis.
  • Io.
    Io.
    abbreviation
    Iowa.
  • I/O
  • I.O.
    I.O.
    abbreviation
    indirect object.

io

1 American  
[ee-oh] / ˈi oʊ /
Or 'io

noun

  • ios
    plural
  1. a small, solitary hawk, Buteo solitarius, having two plumage phases and breeding only on the Island of Hawaii, where it is a rare species and the only indigenous bird of prey: classified as near threatened.


Io 2 American  
[ahy-oh, ee-oh] / ˈaɪ oʊ, ˈi oʊ /

noun

  1. Classical Mythology. a woman who, being loved by Zeus, was transformed into a white heifer and was, at the wish of Hera, first guarded by Argus and later pursued through the world by a gadfly until she reached Egypt, where she resumed her true shape: identified by the Egyptians with Isis.

  2. Astronomy. a large volcanically active moon of the planet Jupiter.


Io 3 American  
[ahy-oh, ee-oh] / ˈaɪ oʊ, ˈi oʊ /

noun

  • Ios
    plural
  1. Io moth.


Io 4 American  
Symbol, Chemistry.
  1. ionium.


Io. 5 American  

abbreviation

  1. Iowa.


I/O 6 American  
I.O. 7 American  
Or IO,

abbreviation

  1. indirect object.


Io 1 British  
/ ˈaɪəʊ /

noun

  1. the innermost of the four Galilean satellites of Jupiter, displaying intense volcanic activity. Diameter: 3640 km; orbital radius: 422 000 km

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

io 2 British  

abbreviation

  1. British Indian Ocean Territory

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Io 3 British  
/ ˈaɪəʊ /

noun

  1. Greek myth a maiden loved by Zeus and turned into a white heifer by either Zeus or Hera

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

I/O 4 British  

abbreviation

  1. input/output

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Io 5 British  

symbol

  1. ionium

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Io Scientific  
/ īō,ēō /
  1. One of the four brightest satellites of Jupiter and the fifth in distance from the planet. It was first sighted by Galileo.

  2. See Note at moon


Other Word Forms

Noun Inflected Forms

Etymology

Origin of io

From Hawaiian ʿio

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

That company alleged last year that a former engineer stole files from the company and handed them over to Tan, then a senior executive connected to io Products.

From The Wall Street Journal Jul. 10, 2026

Tan spent 24 years at Apple, most recently as vice president of product design for the iPhone and Apple Watch, before co-founding io Products, which OpenAI acquired for roughly $6.5 billion in 2025.

From Barron's Jul. 10, 2026

Along with OpenAI, Apple is suing io Products, the design startup founded by Jony Ive, a long-time Apple executive.

From BBC Jul. 10, 2026

Tan left Apple to found io Products alongside Jony Ive, Apple’s former chief design officer, and other leaders.

From MarketWatch Jul. 10, 2026

Wasn't quite midday so the heat wasn’t overbearing and there weren’t no heat waves across the fields io make the eye see things funny.

From "Life Is So Good" by George Dawson

This effect is dramatic on Io, Jupiter's innermost large moon, where intense gravitational stretching drives constant volcanic eruptions.

From Science Daily Jan. 7, 2026

Scientists have long theorized that Jupiter's four large moons -- Io, Europa, Ganymede, and Callisto -- originated from a similar disk surrounding the young planet billions of years ago.

From Science Daily Oct. 29, 2025

But although the planet is known to be smothered in volcanoes, an opaque atmosphere has prevented anyone from seeing an eruption the way spacecraft have spotted them on Io, the hypervolcanic moon of Jupiter.

From New York Times May 27, 2024

“This is a terrestrial planet that I would describe as Io on steroids,” Kane said in a statement about TOI-6713.01.

From Salon May 14, 2024

Io was not the only girl who gained geographical fame because Zeus fell in love with her.

From "Mythology: Timeless Tales of Gods and Heroes" by Edith Hamilton

They are, however, frequently abbreviated thus: Iowa, Ia. or Io.;

From Higher Lessons in English A work on English grammar and composition by Brainerd Kellogg

Tuesday’s Google I/O developer conference failed to pack the sizzle that some investors were hoping for.

From MarketWatch May 20, 2026

The model is beginning with video, but will soon be able to “generate any output from any input,” Demis Hassabis, who leads Google’s DeepMind unit, says at the company’s 2026 I/O conference.

From The Wall Street Journal May 19, 2026

The order is for production of wafer-level test and burn-in of silicon photonics integrated circuits, used in data center optical interconnects and emerging optical I/O architectures for AI processors, according to Aehr.

From Barron's Apr. 3, 2026

Next month, it’ll kick off its always-exciting Worldwide Developers Conference, likely with as many A.I. mentions as Google’s recent I/O had, if not more.

From Slate May 24, 2024

In Great Britain, `fred', `jim' and `sheila' are common metasyntactic variables because their uppercase versions were official names given to the 3 memory areas that held I/O status registers on the lovingly-remembered BBC Microcomputer!

From The Jargon File, Version 4.2.2, 20 Aug 2000 by Guy L. Steele

The senior coalition officer said the insurgents who supported the Qatar process “didn’t do a good I.O. campaign to sell it to their people.”

From New York Times Oct. 2, 2012

Mr. Green next day notified the Canadian Trades and Labor Congress that it must expel 30,000 C. I.O. members or renounce 120,000 A. F. of L. members.

From Time Magazine Archive

To these three the President added Sidney Hillman, pink-cheeked, blond, curly-haired, 53, chief of Amalgamated Clothing Workers of America, vice president of C. I.O., a "labor statesman," no bumbler, coldly intellectual.

From Time Magazine Archive

Between A. F. of L. and C. I.O. there still exists a thin, technical tie: the rebellious C. I. O. unions were suspended last year but they have not yet been expelled.

From Time Magazine Archive

A cabin marked I.O. is entered—every room is a cabin in a naval base.

From Submarine Warfare of To-day How the Submarine Menace was Met and Vanquished, With Descriptions of the Inventions and Devices Used, Fast Boats, Mystery Ships by Charles W. (Charles William) Domville-Fife

Preparations are under way to repatriate the remains of two teenagers from Dublin who died in separate incidents on the Greek island of Ios over the weekend.

From BBC Jul. 4, 2023

In October, they interrogated a submarine cable that connects the islands of Santorini and Ios.

From Science Magazine Dec. 8, 2021

He met Fiona Moore, the woman who would become his wife, on the Greek island of Ios in the early 1990s.

From New York Times Dec. 27, 2016

Last summer, I had lunch in a beach-side taverna on the island of Ios, which I had last visited when it was a hippy haven in the 1970s.

From BBC Jul. 24, 2015

The islands called the Sporades lie to the south and east of the Cyclades, among which are Amorgo, Ios, Sicinos, Thera, and Anaphe—some of which are barren, and others favorable to the vine.

From Ancient States and Empires by John Lord

This week the app overtook WeChat and TikTok to become the most-downloaded app for Apple and ios devices in China, though its popularity is not entirely due to merit.

From The Guardian Feb. 15, 2019

There are a lot of closeups and  difficult-to-decipher geometry, but the intent here is clear — Sony is ios going to show us what the PS4 actually looks like.

From Forbes May 20, 2013

Android is much better, in my opinion, because it is not afraid to make drastic changes to its system. ios has looked similar since the start.

From Time Apr. 21, 2013

Only the brooding golden backlighting that makes theaters out of Parrish's scenar ios bespeaks a pre-neon sensibility.

From Time Magazine Archive

The price is 28,000 10000 in fives and ios 18000 50 and zoos.

From Time Magazine Archive

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