What is the difference between leggings, hosiery & tights?
Questions About Apparel

Here is a good example of why the United States separated from England.  It had nothing to do with taxes as historians have suggested.  The problem is that although Americans and the British both speak English, the United Kingdom uses different fashion terms from time to time.  The below explanation gets a little tricky because the UK and USA have slightly different terms.

Pantyhose (called "Tights" in the UK and a few other countries):  Sheer, close-fitting legwear that covers the wearer from the waist to the feet.  Pantyhose first appeared in the 1960's as an alternative to control panties and nylon stockings.  Pantyhose are designed to be attractive in appearance, hide any visible imperfections, reduce visible panty lines and ease chafing between feet and footwear or between thighs.

Tights (called "Stockings" in the UK):  A cloth garment covering the wearer from the waist to the toe with a tight fit, usually knitted or made of thicker material than pantyhose.  Tights come in absolute opaque, opaque, sheer and fishnet styles or a combination.  Tights used to be worn primarily by men but nowadays, aside from in athletics or ballet, are mostly worn by women and girls.

Stockings (also known as "Hose"):  A close-fitting elastic garment covering the wearer from the toe to somewhere between the knee and mid-thigh, usually of a similar material as pantyhose.  Stockings are held up by elastic, but historically were kept up with a garter belt (which went around the wearer's waist and had suspenders that clipped to the tops of the stockings), stay-ups or garters (bands that went around the tops of the stockings).

Leggings:  Leggings are a type of skin-tight garment that covers the legs.  More similar to pants than pantyhose, tights, or stockings.  Leggings are a skin-tight garment made from a thicker material that covers the wearer from the waist to anywhere between the knee and the ankle, leaving the feet uncovered.