theodolite vs alidad

theodolite and alidad both are nouns.

Word	Noun	Adjective	Verb	Adverb
theodolite	Yes	No	No	No
alidad	Yes	No	No	No

theodolite (noun)	alidad (noun)
a surveying instrument for measuring horizontal and vertical angles, consisting of a small telescope mounted on a tripod	surveying instrument used with a plane table for drawing lines of sight on a distant object and for measuring angles
	surveying instrument consisting of the upper movable part of a theodolite including the telescope and its attachments