from
WordNet (r) 3.0 (2006)
alidade
n 1: surveying instrument consisting of the upper movable part
of a theodolite including the telescope and its attachments
[syn: {alidade}, {alidad}]
2: surveying instrument used with a plane table for drawing
lines of sight on a distant object and for measuring angles
[syn: {alidade}, {alidad}]
from
The Collaborative International Dictionary of English v.0.48
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]