Ploopy is a word and slur made up by Manny, who uses it as an insult to Greg as he takes his anger out on everyone after losing Tingy, his blanket. When he says it, Greg doesn't know what it means. He then asks Susan what "ploopy" means, who also asks, "WHAT IS A PLOOPY?" Manny uses the strange word to his advantage, calling Greg a ploopy.
One day at church, Greg decided to say it to Manny, and when he does, Manny begins to cry, and the Heffleys leave early in embarrassment. At home, Susan bans the word in the family, and nobody can say it or they risk a 2 week grounding.
After it is banned, Rodrick finds a way to get around the censoring by saying the words in separated parts during 3 different days: Pl-(Mon.)oo-(Tue.)py.(Wed.), but Greg did not understand what he was doing until the 3rd day.
- In the online version, the word "pootie" is used instead and was first done by Manny unprovoked.