Plus-fours are a vintage style of men's trousers that are typically shorter than regular trousers and feature a wide, relaxed fit with a cuff at the bottom. Some synonyms for plus-fours include knickers, breeches, jodhpurs, and riding pants. These terms all refer to different styles of pants that have a similar shape and fit. Knickers are typically shorter and worn just below the knee, while jodhpurs feature more of a tapered leg and are often made from thicker, more durable materials. Breeches are typically made from leather or other materials and feature a tighter fit and a high waist. All of these styles have a timeless appeal and can add a touch of vintage sophistication to any outfit.