Loonbath Posted in L Best definition Loonbath To do a plank over your bathtub, and thust into the water repetitively until orgasm is reached. Hey did you see the smile on Jims face, he must have went loonbatheing last night. How satisfied are you with the definition? Looking for Loonbath meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 28 times.