ALIDADE

alidade, alidad

(noun) surveying instrument used with a plane table for drawing lines of sight on a distant object and for measuring angles

alidade, alidad

(noun) surveying instrument consisting of the upper movable part of a theodolite including the telescope and its attachments

Source: WordNet® 3.1

Etymology

Noun

alidade (plural alidades)

(cartography, astronomy, surveying) A sighting device used for measuring angles.

Synonyms

• turning board, diopter (obsolete)

Source: Wiktionary

Al"i*dade, n. Etym: [LL. alidada, alhidada, fr. Ar. al-'idada a sort of rule: cf. F. alidade.]

Definition: The portion of a graduated instrument, as a quadrant or astrolabe, carrying the sights or telescope, and showing the degrees cut off on the arc of the instrument Whewell.

Source: Webster’s Unabridged Dictionary 1913 Edition