Full sail is a term used to describe when a sailboat has all of its sails fully deployed and is being propelled by the wind at maximum speed. Synonyms for full sail include sailing at full tilt, sailing at full speed, and sailing with all sails set. Other terms that can be used to describe the speed of a sailboat include sailing at full throttle, sailing at top speed, and sailing at maximum velocity. No matter what term is used, they all describe the exhilaration of sailing at full speed with the wind in your hair.