A way of admitting a mistake, and apologizing for that mistake, without actually apologizing. The best definition I ever read of this, now paraphrased:

"I did something bad, and I recognize that I did something bad, but there is nothing that can be done for it now, and there is technically no reason to apologize for that error, so let's just assume that I won't do it again, get over it, and move on with our lives."

Ruder than apologizing, but with the same meaning: a flippant apology.
"You just spilled your beer on my term paper!!"
"Er... my bad."
by Lita August 17, 2004
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(n.) A combination of an apology and a dismissal. Basically, saying "oh yeah, I did that, but I don't care".

Persons of an older generation can find this quite annoying to hear when expecting an actual apology.
"Hey, you spilled my Coke all over me!"

"Oh. My bad."

"#@%$!"
by Traffic-Cone-Liberation-Force November 16, 2004
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A way of appologizing when you don't reallly care about the situation. Kind of like saying whatever.
Teacher: Joe, stop texting
Joe: My bad
by a keyboard December 12, 2009
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A term used to tell someone that you made a mistake and apologize at the same time. Originally Used Mostly by African Americans but over the years it has become a more mainstream term; so it is not uncommon any more to hear anyone else (possibly in the professional world too) say it to admit to making a mistake.
Teacher: The answer to #1 is B (then he show his work)
Student: Sir I believe you are wrong. (student explains their answer)
Teacher: My Bad you were right and I was wrong, sorry for the misunderstanding
by Yourname2 April 2, 2007
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A grammatically incorrect way of acknowledging (facetiously) a wrongdoing.
Used very commonly by gangsta-wannabes and other sorts of conforming posers, the terrible grammar tends to drive literate people up the wall in absolute irritation.
"Jared! Did you drop the baby?"
"Oh. Ha. My bad!"
"WHAT THE F?!?!"
by FranzMerlin January 22, 2006
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A term currently used when a mistake is made on your part. Allegedly originating from an unamed African Basketball Player in the 1980's (who spoke very poor english)who said it after missing a free throw. Several Sportscasters heard the phrase and used it as a joke until it became a part of popular culture.
by JorSi November 28, 2007
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A hipster way of admitting a mistake that sounds like a two year old who pooped his pants.
Hip person: oops, my bad.

Two year old who pooped his pants: Oops, my bad.
by bored_at_work March 11, 2007
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