/ Dictionary / Index G geomagnetism: Meaning and Definition of Find definitions for: ge•o•mag•net•ism Pronunciation: ( jē"ō-mag'ni-tiz"um), [key] — n. the earth's magnetic field and associated phenomena. the branch of geophysics that studies such phenomena. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. geomagnetic storm geomancy Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language