D defs.my
Entry 1 sense Webster, 1913

Alidade

· Al·i·dade · IPA /ˈæ.lɪ.deɪd/
01 n. The portion of a graduated instrument, as a quadrant or astrolabe, carrying the sights or telescope, and showing the degrees cut off on the…
  1. 1.
    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