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n. A navigational instrument containing a graduated 60-degree arc, used for measuring the altitudes of celestial bodies to determine latitude and longitude.

n. See Sextans.

n. A navigational device for deriving angular distances between objects so as to determine latitude and longitude.

n. One sixth of a circle or disc; a sector with an angle of 60°.

n. The sixth part of a circle.

n. An instrument for measuring angular distances between objects, -- used esp. at sea, for ascertaining the latitude and longitude. It is constructed on the same optical principle as Hadley's quadrant, but usually of metal, with a nicer graduation, telescopic sight, and its arc the sixth, and sometimes the third, part of a circle. See Quadrant.

n. The constellation Sextans.

n. In mathematics, the sixth part of a circle. Hence An important instrument of navigation and surveying, for measuring the angular distance of two stars or other objects, or the altitude of a star above the horizon, the two images being brought into coincidence by reflection from the transmitting horizon-glass, lettered b in the figure.

n. [capitalized] Same as Sextans, 2.

n. a measuring instrument for measuring the angular distance between celestial objects; resembles an octant

n. a unit of angular distance equal to 60 degrees

"I had to confess that I was not a navigator, that I had never looked through a sextant in my life, and that I doubted if I could tell a sextant from a nautical almanac."

angular unit   

prismatic sextant    box-sextant    octant    Wikipedia article on Sextant    quadrant   

quadrant   

barometer    spyglass    altimeter    chronometer    theodolite    pedometer    hogleg    compass    tangler    refractor