booyakasha is a word that can be used in any situation, at any time, when no other response can be thought of. similar to 'your mum;' if you don't know what to say, simply shout BOOYAKASHA! it ends all arguments. you disagree? BOOYAKASHA! (can also be shortened to 'boo-ya')
"Have you got that twenty pounds you owe me?"
"Booyakasha!" *runs away*