alidade
NounSynonyms:
alidad
WordNet 3.0
Webster's Dictionary (GCIDE)
Alidade \Al"i*dade\, n. [LL. alidada, alhidada, fr. Ar. al-'id[=a]da a sort of rule: cf. F. alidade.] 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. [1913 Webster]