In Reply to: A pair of pants posted by John L. Burgess on January 09, 2009 at 08:16:
: What is the origin of the phrase 'a pair of pants'?
: We have a pair of shoes (two separate objects), but we do not have a pair of shirts?
You are far from the first to wonder about this, and the answer (to me) is fairly interesting. I'll give a shortened version. It may not seem short, but this is a topic which gets more interesting the more it's researched.
The shortest answer is that "pant" refers to a trouser leg, or pantleg, and since they alwa;ys come in twos, the usual word is pants. One historical change is that some garments that started out with long pantlegs have had them shortened in increments in successive periods. Thus, at one time (18th-early 19th cent.) some women wore an undergarment with long, loose pantlegs under their long skirts. These were called pantaloons. As skirts got shorter, so did the garments underneath. In the 1930s women wore an undergarment with loose pantlegs gathered at the knee, somewhat resembling the general character of men's knickerbockers, which English ladies naturally called knickers. American women called them "Bloomers," after Amelia Bloomer who promoted the garment, although she didn't invent it. And they soon started getting shorter, too, so that what was left was so abbreviated that the pantlegs were only nominal, and the garment was given a name indicating the abbreviation, "panties," almost always used int he plural except in the garment trade. And you know the rest. When the garment lost the pantlegs altogether it continued to be called "panties," and when syntactic agreement was required, the plural continued to be used. "I keep my panhes in a separate drawer, where I'll alwalys know where [bold]they[/bold] are."
Men's pants usually still have pantlegs. A bathing suit for men is not called "pants," but rather a bathing suit. Sometimes, in the garment called "shorts," the pantlegs have become so short as to be almost imaginary, but that's not usually the case. In men's underwear the type called boxer shorts has definite pantlegs. The type sometimes called "briefs" used, sometimes to be called "BVDs," after a popular brand. These garments continue to be, grammatically, plural.
The word pants has a long history. It came to the English from the French, who had adopted some of the characters of the Italian [i]commedia dell'arte[/i] (16th-18th c.}, including one called "Pantalon." He was called, in Italian, Pantaleone, and was a kind of old fool, speaking Venetian dialect and wearing a grament with long trouser-legs. Such a name for one representing a typical Venetian was natural, since Pantalone or Pantaleone had become a common Venetian surname, probably because San Pantaleone was the patron saint of Venice (at least from the 10th century).
There may be errors in this account, and I wish you pleasure in finding them in your research. In brief, however, pants are plural because the garment gets its name from the pantlegs, which come in pairs for obvious reasons. (As I mentioned, the garment trade often uses the word "pant" in the singular for the whole garment.)