Salutaion.
Form of greeting and hello's

Actually it is a Jamaican patois approximation of the sound of a gunshot- you hold two fingers in the air and shout "BOOYAKASHA, BOO- BOO- BOOYAKASHA"

straight from the mouth of Ali G himself, in an interview with spin.com

Could you translate your catchphrases "booyakasha" and "wagwaan"?

"Booyakasha" means "listen up rudeboi everytin irie whayaso lickylicky ya wangagot fifiman." "Wagwaan" means "booyakasha."

Booyakasha comes from the Irish word "buíochas" (pronounced bwee ah kuss) which mean "glory to" "or praise be" as in "buíochas le Dia" which means "thanks be to god". Oliver Cromwell sent 1000s of Irish to the plantations in Jamaica, and a lot of Irish (or Gaelic as non Irish people know it) words made it in to Jamaican patois. Another example is "Irie" from the Irish verb "Eirigh" (pronounced "Ire - ee") meaning to get up.

an expression used when someone is destroyed by a verbal smack down. brought to us by ali G& characterized by a snap on the fingers.

1. a quick exclamation used when one has owned, pwned, shanked, kicked the crap out of, or mentally abused someone followed immediately by a quick snap of the fingers.

2. see above for definition

a word in swahili that means "death to the white man"