electromotive forcen. Abbr. EMF The energy per unit charge that is converted reversibly from chemical, mechanical, or other forms of energy into electrical energy in a battery or dynamo.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.electromotive force n (General Physics) physics a. a source of energy that can cause a current to flow in an electrical circuit or deviceb. the rate at which energy is drawn from this source when unit current flows through the circuit or device, measured in volts. Abbreviation: emf or EMF Symbol: E Compare potential difference Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014elec?tromo?tive force? n. the energy available for conversion from nonelectric to electric form, or vice versa, per unit of charge passing through the source; the potential difference between the terminals of a source of electrical energy: expressed in volts. Abbr.: emf Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.electromotive force1. The force that makes electrons move to produce an electric current. Electromotive force is supplied by a power source, such as a battery or dynamo. It is measured in volts.2. The difference in the potential energies of a cathode and anode immersed in the same solution of electrolytes or connected in another manner.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.