Earliest documented use of the word thus far: Used by the Latino hip-hop group Cypress Hill on the album Cypress Hill, which was released on August 13, 1991.
Originally used in the same way as "BANG! GOTCHA!", the definition has expanded with popularity and is most commonly used as an exclamation of triumph, in the same way as "Gotcha," or "So there!" or "Hah!".
Madman gonna get cha, quick with the cuente
See a gang, no there ain't no jugete
Rollin like a pyscho with the windows rolled down
Who you lookin at, you tryin to fade me clown?
Plato, si mon, you want static
When you reach for your gat to load your automatic
(Boo-yaa!!) Spittin out buckshots
Homey say blood claat, so you can call a pig
Cause no one could handle, I wind up, and loco
Insane in the brain, you get the bullet and
(2) Due to the popularity of gang culture in urban areas, the shotgun imitation sound was embraced by urban culture and often used to the point where it came to mean other things, such as "Hell yeah!" "Right on!" "In yer face!" or simply "Yeaahh!"
(3)In the late 90's and early 00's, boo-yaa was embraced by mainstream white culture, and the shotgun meaning was completely dropped and forgotten. In the mainstream white culture, boo-yaa simply became a yell of exuberance or joy.
(4) The Boo-Yaa T.R.I.B.E are an experimental Los Angeles gangsta/alternative rap group. They named themselves after the urban slang word for a shotgun or the sound a shotgun makes when fired.
(2)Boo-yaa, sucka, you got knocked straight out!
(3)Boo-yaa! Yaaay!! I won the game!
(4)The Boo-Yaa T.R.I.B.E are one sick rap group.
you're stuck in my hood, so what ya gonna do now?
-Cypress Hill, "Hand on the Pump" (1991)
Boo-yaa! That stock is a definite buy!
Jim Cramer, Host of "Mad Money" on CNBC (2006)
In the 80's and 90's a mixture of free BASE cocaine, the residuals found at the bottom of the screen, and the resin from the pipe collected together- a collection of leftovers - was smoked. The smoker would then exhale and exclaim, "boo-yaa"