Absurdistan is a made-up word that describes a silly or ridiculous place. It's like a place where things are so crazy that they don't make sense anymore. It's like when you play pretend with your friends and make up silly rules that don't really make sense, like "the floor is lava" or "you can only talk in animal sounds".
In real life, we sometimes use the word Absurdistan to talk about a place where things are very confusing or chaotic. For example, if there's a lot of traffic and everyone is honking their horns and nobody knows where to go, you might say "this is like Absurdistan!" But it's usually just a way to say that things are a little bit crazy, and not really a real place.