Also found in: Encyclopedia, Wikipedia.
n. pl. After·rus·es
A fixed compass card on which bearings relative to a ship's heading are taken.
[Probably named around 1854 by the applicants for the British patent on the device, after Latin Pelōrus and Greek Pelōros, the name of a skilled pilot whom Hannibal is said to have put to death in Messina for treachery (although Hannibal later realized the pilot's faithfulness and erected a monument to him there), probably a legendary name derived from Greek Pelōros, Pelōrias, ancient names of Messina, probably from pelōros, prodigious, monstrous (perhaps from the dangerous whirlpool, winds, and currents of the Strait of Messina ); see peloria.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
n, pl -ruses
(Navigation) a sighting device used in conjunction with a magnetic compass or a gyrocompass for measuring the relative bearings of observed points
[of uncertain origin, perhaps from Latin Pelōrus a dangerous Sicilian promontory]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
pe•lo•rus(pəˈlɔr əs, -ˈloʊr-)
n., pl. -rus•es.
a device for measuring in degrees the relative bearings of observed objects.
[1850–55; perhaps < Latin Pelōrus, now Faro in Sicily, a cape which requires skill in navigation]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.