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."
A ploune is a weaker individual douchebags use to fulfill their needs. A ploune is compliant, often a little stupid and manipulable. The ploune will endure this suffering in hopes of getting the object of their desire - the douchebag.
I was out last night with my boys, we were trying to get it on with a group of plounes.