A type of skirt that leaves one leg exposed by ending around the crotch area on the front and around the side or the back of the thigh area on the other, often worn over a pair of shorts or a shorter skirt, although many times they come as a single piece.
Not to be confused with a showgirl skirt, in which the entire front area is missing, or with a high-low skirt in which the front half is shorter than the back.
If it's clear that it's being worn over a separate skirt, shorts or pants, also tag overskirt.