Definitions
from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun One eighth of a circle.
- noun A 45° arc.
- noun The area enclosed by two radii at a 45° angle and the intersected arc.
- noun An instrument based on the principle of the sextant but employing only a 45° angle, used as an aid in navigation.
- noun Astronomy The position of a celestial body when it is separated from another by a 45° angle.
- noun One of eight parts into which three-dimensional space is divided by three usually perpendicular coordinate planes.
from The Century Dictionary.
- noun The eighth part of a circle.
- noun In astronomy, that position or aspect of two heavenly bodies, especially a planet and the sun, when half-way between conjunction or opposition and quadrature, or distant from one another by the eighth part of a circle, or 45°.
- noun An instrument used by seamen for measuring angles, resembling a sextant or quadrant in principle, but having an arc the eighth part of a circle, or 45°. By double reflection it can measure an arc of 90°. See
sextant . Hadley's quadrant is really an octant. - noun Each of the eight regions into which space is divided by three copunctal non-costraight planes.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Geom.) The eighth part of a circle; an arc of 45 degrees.
- noun (Astron. & Astrol.) The position or aspect of a heavenly body, as the moon or a planet, when half way between conjunction, or opposition, and quadrature, or distant from another body 45 degrees.
- noun An instrument for measuring angles (generally called a
quadrant ), having an arc which measures up to 9O°, but being itself the eighth part of a circle. Cf.Sextant . - noun (Math. & Crystallog.) One of the eight parts into which a space is divided by three coördinate planes.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun The
eighth part of acircle ; anarc of 45 degrees. - noun geometry : The
eighth part of adisc ; asector of 45 degrees;half aquadrant . - noun nautical : An
instrument formeasuring angles , particularly ofelevation .
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a measuring instrument for measuring angles to a celestial body; similar to a sextant but with 45 degree calibration
Etymologies
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
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Examples
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John Paul’s deliverance from the hardship of the lower deck was a brass instrument called an octant.
John Paul Jones 9781451603996 2003
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John Paul’s deliverance from the hardship of the lower deck was a brass instrument called an octant.
John Paul Jones 9781451603996 2003
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Advances in the development of these instruments made such calculations easier and more precise, for example: the "course protractor", the "cuadrant", the "octant and the sextant", and the "longitude clock", which was a precision chronometer.
Sailing on and on 2008
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Advances in the development of these instruments made such calculations easier and more precise, for example: the "course protractor", the "cuadrant", the "octant and the sextant", and the "longitude clock", which was a precision chronometer.
Sailing on and on 2008
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From a private collection, offerings include several important pairs of globes by Newton, a sextant by Ramsden, an octant by George Jones, equinoctial dials, astrolabes, chronometers, microscopes and nautical antiques.
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Curved an eighth of circle, hence “octant”, fixed with small mirrors and etched by degrees, an octant can tell a mariner the angle of the sun to the horizon at high noon.
John Paul Jones 9781451603996 2003
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It was in its octant, and showed a crescent finely traced on the dark background of the sky.
Round the Moon 2003
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Curved an eighth of circle, hence “octant”, fixed with small mirrors and etched by degrees, an octant can tell a mariner the angle of the sun to the horizon at high noon.
John Paul Jones 9781451603996 2003
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Wesley found a packet of small iron tools, an octant and a massive spiked club.
DEBTOR'S PLANET W.R. THOMPSON 2000
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Charred remains of the boat, a burned octant, and a few unexploded cartridges were all that remained of the meager outfit upon which they depended to take them to the mouth of the river, a distance of over 250 miles.
Scientific American Supplement No. 822, October 3, 1891 Various
chained_bear commented on the word octant
"Octant or octile, in astronomy, the aspect of two planets, wherein they are distant an eight part of a circle, or 45 degrees from each other."
—Falconer's New Universal Dictionary of the Marine (1816), 326
October 14, 2008