资料来源 : pyDict

指方规,照准仪

资料来源 : Webster's Revised Unabridged Dictionary (1913)

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.

资料来源 : WordNet®

alidade
     n 1: surveying instrument consisting of the upper movable part of
          a theodolite including the telescope and its attachments
          [syn: {alidad}]
     2: surveying instrument used with a plane table for drawing
        lines of sight on a distant object and for measuring
        angles [syn: {alidad}]