astrolabe

American  

[as-truh-leyb] / ˈæs trəˌleɪb /

noun

1. an astronomical instrument for taking the altitude of the sun or stars and for the solution of other problems in astronomy and navigation: used by Greek astronomers from about 200 b.c. and by Arab astronomers from the Middle Ages until superseded by the sextant.

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astrolabe British  

/ ˈæstrəˌleɪb /

noun

1. an instrument used by early astronomers to measure the altitude of stars and planets and also as a navigational aid. It consists of a graduated circular disc with a movable sighting device Compare sextant

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astrolabe Scientific  

/ ăs′trə-lāb′ /

1. An ancient instrument used widely in medieval times by navigators and astronomers to determine latitude, longitude, and time of day. The device employed a disk with 360 degrees marked on its circumference. Users took readings from an indicator that pivoted around the center of the suspended device like the hand of a clock. The astrolabe was replaced by the sextant in the 18th century.

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Other Word Forms

• astrolabical
  adjective

Etymology

Origin of astrolabe

1325–75; Middle English, variant of astrolabie < Medieval Latin astrolabium < Late Greek astrolábion, Greek astrolábon (neuter of astrolábos, adj. used as noun), equivalent to ástro ( n ) star + lab- (variant stem of lambánein to take, seize) + -on neuter suffix

Explanation

An astrolabe is an ancient instrument used for estimating the altitude and predicting the position of celestial objects, such as the moon, other planets, and stars. The ancient Greeks created most of the fields of study that exist today, and along the way they created many clever devices. One was the astrolabe. An astrolabe had the same purpose as the sextant, which came later: to make astronomical measurements. An astrolabe was portable, and it consisted of a metal disc, a sighting arm, and several rotating parts used in estimating unfathomable distances. The astrolabe was an important invention in the history of astronomy and astrology.

Example Sentences

The pair were part of the so-called "Lahore School", one of the most renowned centres of astrolabe production of its time.

From BBC • Apr. 25, 2026

Whether steering a ship for commercial trade or finding the direction of Mecca for purposes of prayer, an astrolabe harnessed light to manage desires around science and myth.

From Los Angeles Times • Nov. 22, 2024

“As the astrolabe changed hands, it underwent numerous modifications, additions and adaptations,” Dr. Gallante said.

From New York Times • Mar. 12, 2024

Destined for an exhibit in Madrid, the painting was whisked through the Dutch halls, past Johannes Vermeer’s Astronomer studying an astrolabe, before getting stuck in front of a small doorway in the Rubens room.

From Seattle Times • Jan. 26, 2021

Just as the astrolabe embodies the medieval application of mathematics to the heavens, the sector embodies the new technical skills of the mathematician applying himself to the world.

From "The Invention of Science" by David Wootton