1. An ancient astronomical instrument used to measure the positions of stars and planets, and to determine latitude and time.
Usage: historical; technical
2. A flat, circular device with a rotating pointer and marked scales, used in navigation and surveying.
Usage: nautical; historical

Examples

• Medieval astronomers relied on the astrolabe to map the night sky.
• The captain used an astrolabe to determine the ship's latitude during the voyage.
• An astrolabe consists of a brass disk with a rotating arm called an alidade.
• Scholars in the Islamic Golden Age made significant improvements to astrolabe design.
• The museum's collection includes a beautifully engraved astrolabe from the 16th century.
• Before the invention of the sextant, sailors depended on the astrolabe for navigation.