1. something shaped like the curved shell of a turtle
2. a rounded protective structure on a ship’s deck
Usage: nautical

Examples

• The rock formation had a distinctive turtleback shape.
• The hill’s turtleback profile was visible from miles away.
• The ship’s turtleback design helped deflect waves.
• The architect designed a turtleback roof for the building.
• Water rolled off the turtleback surface easily.
• The submarine’s turtleback hull cut through the water smoothly.