Definition of "sextant" [sex•tant]

• A navigational instrument containing a graduated 60-degree arc, used for measuring the altitudes of celestial bodies to determine latitude and longitude. (noun)
• See Sextans. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "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."
• "A sextant is a navigational instrument that measures the altitudes of celestial bodies."
• "Determining this in the 19th century most commonly involved the use of an optical device known as a sextant to measure the position of a celestial object (such as the sun) at a specific time (usually noon)."