placket
The center slit refers to a vertical opening usually found at the back of a garment, such as a dress, skirt, or shirt. It is designed to provide ease of movement for the wearer and allows the garment to drape nicely over the body without restricting mobility.
Typically waistline, or just waist, which is really boring. I guess the hem was always considered of greater importance.
A skirt expander is commonly referred to as a waistband extender. It provides additional room around the waist of the skirt to allow for a more comfortable fit.
The skirt style you are referring to is called a high-low skirt. It features a shorter hemline in the front and a longer hemline in the back, creating a unique and stylish asymmetrical look.
The slit in the back of a jacket is called a vent. Vents can be either single or double, and they help to provide more movement and comfort when wearing the jacket.
Vent
placket
vent
You put her in a slit red pencil skirt w/ a tankini style top
It is not a skirt. It is called a loincloth.
A slit made by a saw is the kerf.
A skirt's edge is called a Hem
The male skirt is called a malo. The female skirt is a pāʻū.
The center slit refers to a vertical opening usually found at the back of a garment, such as a dress, skirt, or shirt. It is designed to provide ease of movement for the wearer and allows the garment to drape nicely over the body without restricting mobility.
It is called a tutu.
The Scottish tartan 'skirt' - is called a kilt.
Trumpet skirt