source: A clipper was a very fast sailing ship of the 19th century that had three or more masts and a square rig.
target: A clipper was a very fast sailing ship. It was of the 19th century. It had three or more masts. A clipper had a square rig.
references: A clipper was a very fast sailing ship. It was of the 19th century. It had three or more masts. A clipper had a square rig.