“my bad”

Of course "bad" is a noun:
1993 Dog World Nov. 28/1 It is a relatively in-depth look at both the good and the bad in commercial canine nutrition.

It looks like it started in the seventies, probably first among basketball players, with a first mention in print 1986 in a basketball publication. It then got taken up by streetball player followed by more general use. Its popularity no doubt increasing after its use in the 1995 film "Clueless".

As for the grammar aspect, as goofy says, of course 'bad' can be a noun, and is listed in my dictionary as such. Other examples - 'The good, the bad and the ugly', 'You have to take the bad with the good', and the British idiom - 'After the sale they were £300 to the bad.' (worse off).

But in any case, this is an informal, if not slang expression, and we really don't need to look for any great grammatical justification for these. People obviously find it useful or they wouldn't use it. And it's been used on this forum by at least once by a very experienced forum contributor, to me in fact.

http://www.phrases.org.uk/meanings/my-bad.html
http://en.wikipedia.org/wiki/My_bad

Corrections:
It then got taken up by streetball players followed by more general use, its popularity no doubt increasing after its use in the 1995 film "Clueless".
And it's been used on this forum at least once, by a very experienced forum contributor, to me in fact.

"my bad" was, and still is, a popular phrase used by Generation X. Said phrase reflects a position of mistake; as in: my bad, my mistake.

It's clearly a noun, as in the phrase "My bad."

We used "My bad" on the soccer pitch way back in the 70's . . . that phrase has been around for a long time . . . it has crept into the everyday vernacular of the normal state of insecurity of the generation X'rs. I hope someone who heard it well before I did has something to offer on the subject.

"My bad" is the informal, abridged version of "Pardon me sir/madam, my mistake." Bad is synonymous with mistake in that sentence, which obviously is a noun.

Sorry @TtheP, but that's my Generation Y reverse-engineered explanation. I never heard it prior to the late 1990s.

And sorry to @chancery.co, I hadn't noticed that you already explained this in the context (my bad!)

I first heard it in 1995? in the film Clueless - a modern adaptation of Jane Austen's Emma. The film is set in L.A. and the characters all use Valley girl slang. Do I actually say "my bad"? As if.

I first heard it in 1995? in the film Clueless - a modern adaptation of Jane Austen's Emma. The film is set in L.A. and the characters all use Valley girl slang. Do I actually say "my bad"? As if.

hakespeare used the term with something like the current meaning, in his Sonnet 112:
Your love and pity doth the impression fill
Which vulgar scandal stamp'd upon my brow;
For what care I who calls me well or ill,
So you o'er-green my bad, my good allow?