placket means: An opening or slit in a garment which allows for the garment’s fitting. Plackets can be found most often at the neck or wrist of the garment. Plackets can be made with either a hem, or other overlapping parts that conceal the placket. Plackets are commonly made up of buttons, zips, hooks or zippers. (in Fashion Dictionary)

What else does placket mean?

A garment’s opening, or slit, at its collar or sleeves, makes it easy to put on. (in Merlin Dictionary)

A pocket is a handy accessory, particularly in a skirt for women. (in Merlin Dictionary)