Today is Katakana Tuesday and today’s word is パンツ.
Yes, it is the katakana transliteration of the English word, “pants.” and these days it does get used to refer to what English speakers call “pants” but, most of the time, パンツ is used for "underpants," NOT "trousers."
“Trousers” are called ズボン (zubon), which comes from a Portuguese word. The first European who came to Japan was a Portuguese, so there are a lot of Katakana words which come from Portuguese
Up until they saw the first European dressed in pants in the 16th century, Japanese men only wore はかま, which is like a キュロット (kyurotto/culotte).
As I said before, these days young Japanese do use パンツ to mean trousers, but if you are talking to an older generaton, call it ズボン, not パンツ.