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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  
/ ī′ō,ē′ō /
  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:

OpenAI bought that company, io Products, in 2025 to spearhead its own device development efforts.

From The Wall Street Journal ● Jul. 12, 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

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

From MarketWatch ● Jul. 10, 2026

The idea for io, which Sir Jony founded last year, grew out of several years of quiet collaboration between the two companies, according to the announcement.

From BBC ● May 21, 2025

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

By adding a grain transport component, the researchers could trace the journeys of icy particles and reconstruct the physical and chemical history of the material that formed Europa, Ganymede, Callisto and Io.

From Science Daily ● Mar. 1, 2026

“The intriguing feature could improve our understanding of volcanism not only on Io but on other worlds as well.”

From Salon ● Feb. 3, 2025

The spacecraft produced the first high-resolution images of the four planets, the rings of Jupiter, Uranus and Neptune, lightning on Jupiter and lava lakes that revealed active volcanoes on Jupiter’s moon Io.

From New York Times ● Jun. 14, 2024

New images of Jupiter's volcano-studded moon Io, taken by the Large Binocular Telescope on Mount Graham in Arizona, offer the highest resolution of Io ever achieved with an Earth-based instrument.

From Science Daily ● May 30, 2024

But whereas the wretched Io had to pay dearly for the distinction, Europa was exceedingly fortunate.

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

The I/O event was “almost entirely commercially driven,” according to Windsor.

From MarketWatch ● May 20, 2026

The AI eyewear will launch this fall in several optical and sunglass styles, per the announcement made during Google’s I/O event.

From Barron's ● May 19, 2026

Gmail Live, announced at this week’s Google I/O conference, allows you to ask your inbox questions aloud, like what’s your flight reservation number or the door code to your Airbnb.

From The Wall Street Journal ● May 19, 2026

Google made the announcement as part of its annual I/O developer conference in Mountain View.

From Los Angeles Times ● May 20, 2025

VM/CMS officially supports a whole bestiary of virtual card readers, virtual printers, and other phantom devices; these are used to supply some of the same capabilities Unix gets from pipes and I/O redirection.

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

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

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

The doors flanking the passages traversed display cryptic lettering, such as I.O.

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

Santorini, Mykonos and Ios, Greek islands known for their party scenes, now offer relaxing alternatives.

From New York Times ● Aug. 24, 2022

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

From Science Magazine ● Dec. 8, 2021

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

He was buried in Ios, and this is his epitaph: 'Here the earth covers the sacred head of divine Homer, the glorifier of hero-men.'

From Hesiod, the Homeric Hymns, and Homerica by Hugh G. (Hugh Gerard) Evelyn-White

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

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

From Time Magazine Archive

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

From Time Magazine Archive

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