No surprises in the first part of the journey back in time: panties is a diminutive of pants, itself a clipped form of pantaloons. Nowadays, this last word usually refers to trousers, but in the 17th and 18th centuries, it meant ‘tights’. English borrowed it from French (pantalon), which in turn had snatched it from Italian (pantalone).
Within Italy, the word had a very precise origin: Venice. Pantalon used to be a common first name here, which is why the name was chosen for one of the stock characters of commedia dell’arte: the selfish and greedy Venetian merchant. His characteristic woollen tights got to be named after him.
But is this sufficient to call the origin of panties venerable? I’d say not, because commedia dell’arte was after all just the folksy counterpart to the more refined commedia erudita. However, the story goes on, further upstream. The reason why Pantalon became a popular first name in Venice was the local veneration of Saint Pantaleon. A bone fragment of the good man is conserved as a relic in the Saint Pantaleon Church, locally known as Chiesa di San Pantalon. While the building is as recent as the 11th century, its patron saint lived and was martyred around 300 CE, not in Italy but in present-day Turkey, then part of the Greek-speaking Eastern Roman Empire.
And here, we’ve come to the end of our etymological quest into panties, for the saint’s Greek name, Pantoleon, translates as ‘all lion’. So what does women’s undergarment conceal, according to historical linguists? A roaring big cat.