1. noun An outright dismissal of some argument as being unworthy of consideration or debate. My idea could save the company millions, but I'm still expecting a poo-poo from the board of directors because of how radical it is.

2. verb To dismiss something outright, without any due consideration or debate. Don't poo-poo her idea before she's had the chance to explain the ins and outs of it! He's always poo-pooing his assistant's ideas.

3. noun, childish slang Feces. Please don't touch that diaper, it's full of your sister's poo-poo!

4. verb, childish slang To defecate. Our son came running in from the playroom to tell us he needed to poo-poo. Mommy, Daddy, I poo-pooed in my bed.