Definition of alidade
: a rule equipped with simple or telescopic sights and used for determination of direction: as a : a part of an astrolabe b : a part of a surveying instrument consisting of the telescope and its attachments
Origin of alidade
Middle English allidatha, from Medieval Latin alhidada, from Arabic al-ʽiḍāda the revolving radius of a circle
First Known Use: 15th century
Learn More about alidade
Britannica.com: Encyclopedia article about "alidade"
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