There are so many names for that area between the groin and the belly button. Pooch, Bunt, Kangaroo Pouch, etc. For women who have previously born a child, it can be puffy and one of the toughest areas to target.
But could the way you're walking be preventing those lower abdominal muscles from strengthening -- creating a nice vacation home for fat? Two common forms of posture for standing and walking, is hips tucked in or booty hanging out. That would be the first picture and the fourth picture.
When you walk and stand in the number one position, hips tucked in, your lower abdominal muscles engage and tone in a smaller straight alignment to the sacrum of the spine. Over time, these muscles will tone and squeeze out the fat between the layers of muscles.
Now go to the booty out picture in number 4. By sticking your butt out, you are not tightening you core muscles, you are actually puffing them out. The muscles can build and form in almost a convex curve as opposed to a straight tight fiber bundle. The fat then adheres and follows the shape -- allowing for a more bulbous front then most of us would like.
So once again, the easiest way to a better shape over time... is posture. Tuck those hips in and soon you will continue to do so without effort. It's not an overnight correction. It will take months. But walking with your butt hanging out is like undoing all those crunches and sit ups you do every day.
Muscle Bonus: If you want to tone that lower abdomen faster, here's an exercise for you... heels to the heavens.
After this position, comes the crunch. Leaving the middle spine on the floor, bring the shoulders and chest up slightly and get your talbone up off the floor in short bursts. A modification for this would be leaving the shoulders back and arms on the ground and just raising the legs and the tailbone. Hence raising your heels to the heavens.