The Oxford Dictionary of Etymology tells an interesting story of the origin of the word knickerbockers.
In 1809 Washington Irving, who is famous for the short stories Rip Van Winkle and the Legend of Sleepy Hollow, published a book called History of New York. The book was published under the pen name Diedrich Knickerbocker. Pictures of the supposed author showed him wearing loose breeches, which then took his name.
However, that’s not the whole story of knickerbockers. Sometime in the 19th century the word was abbreviated to knickers, a word which will send young British children (and even those old enough to know better) into helpless laughter. The reason? Knickers are the common British term for women’s underwear.