A proud and loud mother who incorrectly thinks that everyone within earshot (and beyond) wants to hear the "adorable" conversation she is having with her small, "precious" child. Plouders are particularly prevalent on airplanes.
"All I wanted to do is sleep on the plane, but instead I had to hear a plouder talk to her daughter about clouds and other boring shit. I thought about turning around and complaining, but then I would have looked like a total dick."
The thing you say, when a big polish man with hair that looks like the barcode on the back of your milk, begins spitting vodka droplets on your face when telling you about this squirrel he ran over.