A long spindly rock formation, found in caves, that protrudes from the cave wall in a horizontal fashion. This formation is similar in appearance to a stalactite or stalagmite but much less common.
Mark: Oh my god, come check out this stalagtron.
Will: You have got to be kidding.
Mark: No way, check it out, it's at least 13 feet long and completely horizontal.
Will: Get the hammer, we're never going to have to work another day in our lives.