Clipper ships were a type of multiple-masted sailing ships used on Earth beginning with the 19th century.
In the mid-20th century, the mission insignia for Apollo 12 depicted a clipper ship sailing above Luna. (ENT: "First Flight")
The command/service module for this mission was named Yankee Clipper, in honor of the clippers built in New England.
Travis Mayweather kept a model of the clipper ship Sea Witch in his old quarters aboard the ECS Horizon. (ENT: "Horizon")
When Data met Guinan in San Francisco in the year 1893 and told her he was from the Enterprise she asked whether that was a clipper ship, not knowing about her future stay on the USS Enterprise-D, the ship Data was referring to. (TNG: "Time's Arrow")
The Akaali built similar three-masted clipper ships as the crew of the Enterprise was able to observe from orbit when visiting the Akaali homeworld in 2151. (ENT: "Civilization")