A trend of crossover videos that feature an animated movie or television show and insert clips and footage of characters from unrelated or connected source material into it like they are actually part of the action. Despite the name, these videos can have any characters in them and some don't even include Pooh characters. There are also quite a number of name variants (eg, Thomas' Adventures, Twilight Sparkle's Adventures) but they're all the same thing.
Pooh's Adventures of Urban Dictionary sounds like a great idea... Oh wait, it IS a good idea!