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A british* acronym for instead of.
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
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
Acronym for Irrelevant One
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

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
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.
"Dude, I wanna dip it in the new workstudy sittin in the corner desk..."
<end of converstion>
by Big G Funk November 03, 2008
Jovian moon that orbits around the planet Jupiter.
by u.ber. August 21, 2003
in•for•ma•tion o•ver•load

1. Business. Sadistic practice in
which a subordinate is given
ambiguous instructions to
complete arbitrary tasks. Also
see “spreadsheets.”
2. Computer Science. Loss of
superhuman state due to
executing subhuman tasks
normally performed by automated
systems. Also see “Windows.”
3. Law. Conditional state reached
in the first year of Law School.
Also see “BAR Exam.”
4. Math. Required state to attend
courses involving “string” in
their title. Also see “MIT.”
5. Medicine. Conditional state
reached in the forth year of
Medical School. Also see
6. Physics. Conditional state
reached during doctoral
dissertation in which common
sense is overwritten with
theoretical knowledge. Also see
“Steven Hawking.”
Superhumans suffer io due to subhumans lack of understanding technology.
by Corey Lohr June 04, 2004