A tremendously unkempt bush covering a woman's genitalia. Much like the biblical figure Samson, the power muff derives its strength from from its length, fullness and overall unruly presentation. It may rise up toward the naval (upper Puff), down the buttocks (Powder Room Muff), but the most powerful of these muffs covers both of these areas much like that of a gorilla's fur. A contrast to the popular pubic dressing of a Brazilian wax, it is ironically revered and eroticized by many in the modern world (see Hipster).
Dude, I love to watch my junk disappear in her power muff when we're dry humping.