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1.
a name used to substitute someone's real name so they don't know you are talking about them. It comes from the vietnamese word for diarrhea (lao sai)
Person 1: Dude did you see what Sai Lao did the other day?
Person 2 (Sai Lao): Who's Sai Lao?
Person 3: Yeah man! What a Dumbass!
Person 2: Who?!?
by Puchley September 12, 2008