When did the word "bad" become a noun?

When did the word "bad" become a noun? I assume it was when the cliche "my bad" was invented. When/where did this originate? Are there any other uses of "bad" as a noun?

I'm specifically interested in the use of "bad" as in "my bad", which seems to mean a specific culpable action on the part of the speaker/writer. This seems distinct from the more abstract uses of "bad" given in the first answer below.

Solution 1:

According to Chapman & Kipfer, Dictionary of American Slang, Third Edition (1995), the interjection "my bad" arose in the 1990s and its source is "teenagers":

my bad interj 1990s teenagers: My bad: My fault or my mistake. A term of apology. —Daily Record

I first heard "my bad" used (in the San Francisco Bay Area of California) around 1994 from a college-age person in the context of a turnover—an errant pass, I believe—committed during a pickup game of basketball.

Inspired by tchrist's excellent addition to his answer, I checked the Elephind newspaper database to discover its earliest instance of "my bad." The earliest appears to be from the "Unclassifieds" section of the [Washington, D.C.] American [University] Eagle (February 8, 1988):

And "Dove Bars At Night Horowitz": Are you related to.... No? Oh, well, my bad. What do you mean, "on my own?!" That's not nice. As my mother always said, "Remember what Thumper's mother said?" My mother wasn't very original. She wasn't as bad as my dad though, he quotes Bill Cosby. -Jesus

This instance corroborates tchrist's citations indicating that "my bad" was in use in parts of the United States in the 1980s. It also provides explicit evidence that the expression had entered college slang (at one Washington, D.C. university, anyway) by early 1988.

In addition, it may be the first identified instance of "my bad" that has no connection to sports. The second and third instances cited by tchrist (from 1986 and 1987) are clearly sports related, and the first instance (from 1985) probably is: Although the wording ("Oops, my bad, I forgot for a moment what the Commodore did to Georgia. Silly me.") is rather opaque, I'm pretty sure that it refers to college football, given (1) the time of year (November 14), and (2) the fact that Gainesville is the home of the University of Florida, which (3) is a traditional rival of the University of Georgia, both of which (4) play in the NCAA's Southeast Conference, as does Vanderbilt University, whose team is called the Commodores, and which (5) pulled off a shocking 13–13 tie against the heavily favored University of Georgia team on October 19, 1985. Perhaps the Florida writer alluded to that earlier game in response to gloating from one or more Georgia fans, because on November 9, Georgia had defeated Florida (which had been ranked number one in the nation prior to the game), 24–3.

Solution 2:

Per the OED, bad became a noun long ago and far away.

• 1591 Shaks. Two Gent. II. vi. 13 — T’exchange the bad for better.
• 1592 Lyly Mydas V. ii. 57 — An inventorie of all Motto’s moveable baddes and goods.
• 1869 Ruskin Q. of Air §125 — But, as there is this true relation between money and ‘goods,’ or good things, so there is a false relation between money and ‘bads,’ or bad things.

There are also these sorts of uses:

• 1884 Pall Mall G. 6 Feb. 4 — He was between £70 and £80 to the bad.
• 1953 K. Amis Lucky Jim v. 57 — This ought to put me nicely in bad with the Neddies.

The expression my bad comes out of AAVE, and per the OED means:

• colloq. (orig. U.S. Sport). With possessive: a person's fault; responsibility for a mistake, blunder, etc. Originally and chiefly in my bad (used mainly as int.).

The first citation is extremely recent in 1985, and the all early ones were from the American South or in sporting contexts. For example, here are a few of them:

• 1985 Gainesville (Florida) Sun 14 Nov. 3 ᴇ/2 — Oops, my bad, I forgot for a moment what the Commodore did to Georgia. Silly me.
• 1986 C. Wielgus & A. Wolff Back-in-your-face Guide to Pick-up Basketball 226 — My bad, an expression of contrition uttered after making a bad pass or missing an assignment.
• 1987 Dallas Morning News 9 Dec. b11/4 — 245-pound sophomore center Dwayne Schintzius [is] not out to hurt anybody. He jabbed me in the eye, and he said, ‘My bad.’ He didn't mean to do it.
• 1993 Orlando Sentinel (Nexis) 3 Dec. c3 — The Litterial Green Collection... Oops, my bad... A release from the marketing hotbed of America.

Solution 3:

I'm English born and bred, editor of a professional journal and published writer on social issues, so the English language and the accurate use of words is important to me, professionally. I've only heard the expression 'my bad' used during the last couple of years and only by Americans. To my knowledge, I've not heard anyone British use the term. Personally, I find it an irritating and incomplete phrase and always want to ask 'your bad what?' I use an up-to-date, two volume OED which says the word 'bad' originated with Middle English & is now an adjective, noun and adverb. 'My bad' is given as an American colloquial expression that originated between 1970 and 1999.