A fork of Rural Dictionary
A walking simulator is a type of video game which lacks many of the traditional aspects of a game (such as a goal, win/loss conditions, any kind of game system to interact with) despite taking the form of a video game. The phrase implies that there is basically nothing to do in the game other than walking around.
A: I sent you a new game on Steam, check it out. B: Gone Home? That's not even a game, it's a walking simulator.
A rare medical condition that causes the patient to not have a reflection in mirrors. There is currently no explanation for this condition. It affects less than 0.01% of the population.
(regarding a goth) "She's such a loser. I bet she wishes she had Maartechen Syndrome."