A battle cry. Generally for young black ghetto warriors to yell before they throw their shit down, be it gang related or otherwise. If you are not a black ghetto warrior and happen to hear the call then be warned: millions of thugs will swarm out of every availabe port. Generally, a gallon of koolaid can hold 80 of them for example, while a seedless watermelon will explode with 200 at least.
White man:"What was that sound?"
Black ghetto warrior:"Uda! Uda uda uda!"
White man:<Dead due to countless bullet wounds.>