It is known as the grundle.
Chances are you have never seen your own grundle. You could consider it the South Pole of your torso. Its the epitome of where the sun don't shine. In fact, unless you are performing hand stands at a nudist resort in the middle of the day its unlikely to ever see any sunlight. That's a shame actually since this area could use some fresh air. If you haven't figured out by now which piece of fleshy real estate I'm talking about then I suggest you check out its urban dictionary definition.
Its likely that you have not paid it much attention. But let me tell you why its time we pay our grundle some respect. I happened to be thinking about mine a few times this weekend after workouts. Ever go cycling? Guess what part of you has to be pressed against the seat the whole time? That's right, your grundle. Since it had been awhile for me to do any cycling I felt numbness in my nether regions once I got out of the saddle. And it seems that the northern terminus of the adductor muscles are in the grundle region. Its these adductors that have been flaring up and bothering me for a month now. So after a run I feel the sharp pain down there. Finding the right method of treating these adductor flare-ups naturally involves the grundle. Icing the region helps. Some types of stretching may also help.
Therefore, as endurance athletes it isn't fair to ignore the grundle. It actually plays a vital role in our lives. Take care of it and it will take care of you.