A gaff topsail is a type of sail that is set on the gaff of a sailing vessel. It is often used on traditional sailing vessels and is typically made of lightweight canvas or synthetic materials. For those looking to expand their nautical vocabulary, there are several synonyms that can be used to describe this type of sail. Some of these synonyms include driver, flying jib, spinnaker, and kitesail. Each of these terms refers to a different type of sail, but they can all be used interchangeably with the term gaff topsail to describe a sail that is set on the gaff of a sailing vessel.