An acronym for "in equivalence", often used to mean "in other words" or "that is". However, it must be noted that "i.e." can only be used when writing. Never say "i.e." in a conversation, unless you want to sound like an idiot.

Don't listen to those who claim "i.e." comes from latin: it doesn't, quite obviously.
Here is an example of how "i.e." is used in a sentence, i.e., a demonstration of how "i.e." can be utilized in a sentence.
by EpicScientician December 6, 2021
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abbreviation for "id est," Latin for "that is"; also means, "in other words." it is followed by an explanation, specific list or a paraphrase.

compare with e.g.

also reference: www.getitwriteonline.com/archive/061801.htm, another comparison of i.e. and e.g.
i like music (i.e., the ordering of tones or sounds to produce rhythm, melody and/or harmony.)
by ambercat May 8, 2005
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Abbreviation used to clarify something, to narrow something, or to specificate. This form is used ONLY in writing, this is too strange in speaking.
I would dig in some pizzas, i.e. the italian one.
by egava August 20, 2015
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Pronounced ‘Aiy’ ‘Ess
Short for Infatuated Spaz. A person who is so besotted by someone that they don’t mind being verbally or physically abused by them.
“Hey man you really shit on your girl don’t you?”
“Don’t worry about her she’s my I.S.
by Prime Dean July 29, 2018
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High School computer geeks usually go on to lucrative careers in I.S. departments.
by Tom Cumbow January 23, 2004
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