from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Differences in the earth's magnetic field in time and location.
- n. See magnetic declination.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. In navigation, at a given place and time, the horizontal angle between the true north and magnetic north measured east or west according to whether magnetic north lies east or west of true north.
- n. In cartography, the annual change in direction of the horizontal component of the Earth’s magnetic field.
from the GNU version of the Collaborative International Dictionary of English
- n. Same as magnetic declination.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the angle (at a particular location) between magnetic north and true north
Sorry, no etymologies found.
The observations of Borrus on the magnetic variation of the compass appear to be of more importance, but unfortunately they have not yet been published.
Moreover, the magnetic variation is 18 degrees 3 degrees at Talcahuano April 23rd, the true meridian bearing to the right of the magnetic.