The first time I personally heard "slay" as a slang word was when Gaga said, "born this way, born to slay"

Do we have any earlier references?

It’s a popular skill you can train on Runescape, the receipts don’t lie

The Ballroom scene I think

where did "YAAAAAASSSSSSSSSS" come from?

From Gaga's Born This Way Ball Tour's men's bathroom

Yeah. I think it dates back to the 60s/70s.

The first time i heard someone say it it was from a white girl so they are the creators of the word i believe! Also hunty

It's a word meaning to kill violently. Past tense is slain, often mistaken for slayed.

In the complimentary meaning it came from Drag!

this

...like the incorrect pronunciation of yes? ("yas"). That is how "ha" came about too.

You wouldn't catch me saying 'slay' in public but 'kill it' however has the same meaning, and I sound less of a twat.

Buffy

What's it gonna be by busts rhymes and Janet Jackson! Listen to her vocals she says YASS

http://dictionary.reference.com/browse/slay

slay
[sley]
Spell Syllables
Synonyms Examples Word Origin

verb (used with object), slew, slain, slaying.
1. to kill by violence.
2. to destroy; extinguish.
3.sley.
4. Informal. to impress strongly; overwhelm, especially by humor:
Your jokes slay me.
5.Obsolete. to strike.
verb (used without object), slew, slain, slaying.
6. to kill or murder.
noun
7.sley.

Origin of slay: Middle English/Old English

Synonyms Expand
1. murder, slaughter, massacre, butcher, assassinate. 2. annihilate, ruin.

Like slaying dragons and ****, I'd hear it in medieval fantasy tales and whatnot which is why I always find it so odd/funny that the gays picked it up. Also don't forget Buffy the Vampire Slayer hihi

This .gif slays me.