What are "plus fours"?

Plus fours are a type of loose-fitting men's trousers, also known as knickers or breeches, that extend to four inches below the knee, typically worn for outdoor sports such as golf or hunting. They were popular in the early 20th century and are characterized by their baggy appearance, which tapers towards the knee, and the fact that they are often worn with tall socks. The name "plus fours" comes from the fact that the trousers are four inches longer than traditional shorts or breeches. While they are not as common today, they are still worn by some golfers and as part of vintage or retro fashion styles.