Waso Share definition Flag Waso (Noun): A put down to another person after they do something foolish. Mike - "I called Chris a waso after he face planted the wall." Bill - "Chris is a dumbass." Waso by Paso Robles Slang January 12, 2011 0 0 Get merch Get the Waso mug. Buy Now — $32.95 See more merch