mag·ne·to·re·sis·tance (m?g-n??t?-r?-z?s?t?ns)n. A measure of the degree to which a conductor or semiconductor changes its electrical resistance when a magnetic field is applied.mag·ne?to·re·sis?tive (-t?v) adj.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.mag?ne?to?re?sist?ance (mæg?ni to? r??z?s t?ns) n. a change in the electrical resistance of a material exposed to a magnetic field. [1925?30] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.