If you're talking about we wear to cover our legs when we're wearing a skirt or dress, it's 'pantyhose' in US English and 'tights' in British English. 'Panty-stockings' is a nice-sounding word, but I don't think it exists. Leggings are different from pantyhose/tights, because leggings don't have feet attached. They're also thicker than tights/pantyhose/stockings, so you can wear leggings in the same way as a trousers or jeans i.e. without a skirt.

pantyhose