mountain butt
A large muscular butt. Found mostly in mountainous regions as a result of walking in the mountains, but could also be achieved by working out the glutios maximus. Pertains to the curve coming down the back to the ass that sticks out far enough to rest a drink on it. Does not pertain to hips.
Look at the mountain butt on that chick!!!
Rocky Mountain Butt Disease
A disease mostly affecting people from tropic and sub tropics environments, RMBD is contracted when one of these people attempt spending a winter in the Rockies, and then end up staying indoors for 5 months. Symptoms include, but are not limited to, an increase in waist size, and a much larger gluteus maximus, pale pasty skin, and a smell of poor hygiene.
Jane moved here last summer from Cali and ended up catching Rocky Mountain Butt Disease.