sextant
/ˈsɛkstənt/
noun
- An instrument used for measuring the angle between two visible objects, especially the sun and the horizon, to determine latitude and longitude at sea.
- Before GPS, navigators relied on a sextant for accurate ocean crossings.
- The sailor used a sextant to find the ship's position far from land.
- He carefully adjusted the sextant to measure the angle of the North Star.