It's when you Jinx someone. You make a motion that your sprinkling them or what they are doing with a fine powder then shout "Guba Dust" 1-3 times.
Friend: watch me bowl this strike...
You: *outreached hand sprinkling at them* "Guba dust, guba dust, guba dust."
or
Friend: Yo i'm gonna roll seven with your duckets on the table...
You: *waves hands over the dice* "guba dust, guba dust, guba dust."
You: *outreached hand sprinkling at them* "Guba dust, guba dust, guba dust."
or
Friend: Yo i'm gonna roll seven with your duckets on the table...
You: *waves hands over the dice* "guba dust, guba dust, guba dust."
by Sir Jamokeous November 16, 2010