I don't know how it happened. First, she would just yell it for fun. An exclamation. It had nothing to do with the contents of her diaper. She would be walking down the hall and yell, "Poop!" and laugh hysterically. I have to admit, coming from a sweet little two-year-old girl, it was hilarious.
But then it started getting a little out of control. As in, we're eating dinner and Ella yells, "Poop!" and throws her head back with laughter. Or, we're at the grocery store picking out bananas and Ella yells, "Poop!" as she smiles at the little old ladies. You get the picture.
And now it's become a nonchalant addition to her vocabulary. Last night we were eating dinner and she didn't want to eat her applesauce. Me, pushing her bowl close to her: "Ella, eat your applesauce." Ella, pushing it away: "Me put poop applesauce right here." She didn't even yell. Or laugh.
Now it's an adjective.
I'll let the people at Merriam-Webster know. I'm sure they'll be as excited as I am.