Pants/pænts/ Definition 1 of 4Pro Tip 1/3Cultural Variance In the UK, 'pants' can refer to underwear, not outerwear. Remember in America, 'pants' means your outer trousers. Pro Tip 2/3Casual Attire 'Pants' is often used for casual clothing, less for formal wear. She has many casual pants but only a few dressy ones. Pro Tip 3/3Not Always Denim Jeans are a type of pants, but not all pants are jeans. I prefer khaki pants to jeans for work.