Pants is an English word used to describe two classes of garment, depending on the dialect. In most dialects of English, including Australian, Canadian, and American English, "pants" are a long bifurcated cloth garment worn over the waist, hips, and legs, formerly thought of as male dress but more recently worn by both sexes. In British English however, this garment is known as trousers, and "pants" are any of a wide variety of short garments covering the genitals and worn under outer clothing. Outside of British English, this garment is known as underpants.
The word "pants" has a long and interesting history. In a long and winding journey across four languages, the term actually derives originally from the Greek combining form panto-, meaning "all" or "every" and thus shares a common root with "Pan-American," "Pan-Slavism," "Pangloss," "Pantomorphic," "Pantological," and the Greek nature god Pan.
It turns out that a common personal name in Ancient Greek was "Pantaleon," which means "the all-lion" or "the everylion," or possibly even "lion of Pan." The name dates at least back to the late Hellenic Period when there was a king of Bactria named "Pantaleon" (reigned ca. 180-190 BC), but became an extremely popular name across Europe during the Roman Empire and into the Middle Ages.
The most famous of all these Pantaleons was Saint Pantaleon, an early Christian martyr of Greek extraction who was executed at Nicomedia in Bithynia during the Diocletian Persecution of AD 303. During the high Middle Ages, Saint Pantaleon was elevated to the elite cohort of saints known as the "Fourteen Holy Helpers" - a select group known to be particularly responsive to prayer and particularly effective in solving worldly problems. Pantaleon was especially known for healing the sick (always a good line to be in if you're a deity or demigod), and was honored across Europe with countless shrines, churches, and monasteries. He was equally important in the Eastern church, where, as Saint Panteleimon, he was part of a similar group known as the "Holy Unmercenary Healers."
Saint Pantaleon was particularly popular in the city-state of Venice, becoming one of the city's patron saints, and the city was so rife with shrines to him that people began calling the Venetians pantaloni, i.e. "Pantaleonians." It was thus not surprising that when other Italians wanted to create a stock character to mock Venetians, they named him "Pantalone."
The commedia dell'arte is a form of comedic improvisational theatre which began in Italy during the 1500s and is still performed to this day. In the commedia dell'arte, troupes of traveling players would wander from town to town giving outdoor performances that featured juggling, acrobatics, and short plays improvised around common themes featuring instantly recognizable stock characters. One of the most common of these characters was Pantalone, the libidinous, miserly Venetian merchant whose lust for young women whom he cannot satisfy is exceeded only by his lust for gold. Pantalone was easily recognized by his mask with a long hooked nose, tight red vest, red Turkish slippers, red skullcap, black cassock, and his unusually long tight-fitting red breeches. These breeches were so distinctive, that they became known as pantaloni, and set off a 16th century clothing fad.
The word was soon borrowed into French as pantalon, where it was used to describe similar items of clothing, and eventually made its way into English as "Pantaloon" where it became associated with the clothing also known as "trousers" ("trousers" being derived from the Welsh word trews, meaning pants or trousers). At this point, the word underwent a curious transformation, becoming plural as "Pantaloons" despite the fact that it is was singular in French, probably by analogy with trousers, which is another plurale tantum (plural word with no singular form).
For a time, the terms "pantaloons" and "trousers" coexisted as synonyms, but languages abhor exact or nearly exact synonyms so this did situation not last long. In America the word "pantaloons" came to be equated with less formal dress, often that worn by women, children, or lower-class persons, which is probably why it was allowed to be shorted to the more casual sounding "pants." This process began in the early 19th century, but the first to use the word "pants" in print with its present meaning was, believe it or not, none other than Edgar Allen Poe, in a satirical 1840 short story, "Peter
Pendulum, the Business Man." Indeed for many years the short form of the word was thought vulgar and crass, or in the words of Oliver Wendell Holmes, "a word not made for gentlemen, but 'gents.'"
Today however, the word has lost any sense of vulgarity, as well as any sense of connection to ancient Bactrian kings and early Christian martyrs, and we are free to wear hot pants, beat the pants off our opponents, fly by the seat of our pants, get into someone's pants, pants Johnny in front of the whole class, wear the pants in the family, or be caught with our pants down.