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One of the four Galilean moons of Jupiter, so called because of being discovered by Galileo. The most volcanically active object in the Solar system.
Hey, look in my telescope: you can see Io, Europa, Ganymede, and Callisto.
by antinous February 02, 2004
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Apr 22 Word of the Day
When you eat dirt for the first time and leave your family to build a shack in the woods
Bro since I got dirtpilled on Tuesday I have made sooo many worm friends and made them soo many little houses to get married in. Me? Lonely? No you’re the lonely one u lawn owning freak
by ecogoth December 30, 2020
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2
Kimmie nicknamed herself IO after falling for Ben's crap for time one hundred. I hate to agree but he sure doesn't seem to care much about her feelings.
by Shyantha December 20, 2006
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3
Acronym (Slang) for "I'm Out" when conversing using the Microsoft Communicator Software. v. The act of hastily departing an online collaboration session with little notice to others participating in the dialogue.

I am no longer part of this conversation as it is digressing rapidly; it will inevitably over-step that invisible moral line in the sand that uniquely distinguishes the employed from the homeless.
<message>
"Dude, I wanna dip it in the new workstudy sittin in the corner desk..."
<reply>
"IO"
<end of converstion>
by Big G Funk November 03, 2008
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4
IO

Instant Orgasm, used by girls to describe something they find attractive and or hot.
"Wow! that sports car is cool." "Yeah! its a total IO."
by aussieslang101 November 11, 2009
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5
Daniel: "Your Craigslist buyer backed out..."
Marianne: "IO."
by mabmoney June 09, 2015
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6
The lecture is on Tue io Thu.

OR (it may be used with dots)

I bought some bananas i.o. apples.
by veekadikoydegskupayialiyor December 31, 2012
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