The plurality of pants

Have you ever noticed that any clothing meant to accommodate both legs is a plural noun? I thought about this today while running errands. (Fascinating what territory the mind will wander into when left to its own devices for any period of time, no?)

Here are some of the items I came up with during my reverie:

pants, trousers, slacks, tights, shorts, capris, overalls, bottoms, long johns, jeans, dungarees, corduroys, waders, pedal pushers, high waters, britches, drawers, panties, chinos, knickers, bloomers ...

Some would dispute my linguistic theory by pointing to "underwear". However, that term can be used to describe items of clothing not meant to cover the nether regions (bras, slips, girdles, etc. can be referred to as 'underwear').

The term 'panty hose' is plural. As a matter of fact, even 'hose' is plural alone. I don't think there is a singular form of the word.

(Assumption: Dresses and skirts do not actually accommodate the individual existence of both legs.)

Why do legs get special treatment in couture? Coverings for the top half of the boody that accommodate the existance of two arms are not plural. (blouse, shirt, top, etc.)

If you can think of a word for an item of clothing that is designed specifically to accommodate both legs simultaneously, but is not plural, PLEASE let me know. Inquiring minds want to know.