A flounce is a design detail in garment sewing that's similar to a ruffle but is usually wider and flatter on top. In this particular demonstration, it makes up the neckline and can appear gathered or ungathered at the top, depending on how stretched it is. This one has a casing with elastic running through it, allowing this design to be worn off the shoulder. It's a lovely look for both dresses and tops. If you have this element in your pattern, some of your steps my be different. For example, maybe you might have sleeves while I do not have any sleeves. Obviously, you'll want to follow your directions as they are written, but this demonstration should still give you a good idea on how it's down and be helpful.
Flounce Neckline