al·​i·​dade ˈa-lə-ˌdād How to pronounce alidade (audio)
: a rule equipped with simple or telescopic sights and used for determination of direction: such as
: a part of an astrolabe
: a part of a surveying instrument consisting of the telescope and its attachments

Examples of alidade in a Sentence

Recent Examples on the Web Lookout Jodi King shows correspondent Conor Knighton the Osborne Fire Finder, an alidade with two sighting apertures used to pinpoint the location of a fire. CBS News, 15 Aug. 2021 Dalton showed the couple around the lookout, explaining the old telephone system and the fire finder, a type of alidade used by fire lookouts., 29 Sep. 2019

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'alidade.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Middle English allidatha, from Medieval Latin alhidada, from Arabic al-ʽiḍāda the revolving radius of a circle

First Known Use

15th century, in the meaning defined above

Time Traveler
The first known use of alidade was in the 15th century

Dictionary Entries Near alidade

Cite this Entry

“Alidade.” Dictionary, Merriam-Webster, Accessed 25 Feb. 2024.

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