1. Physics A pair of separated electric charges or magnetic poles, of equal magnitude but of opposite sign or polarity.
2. Chemistry A molecule having two such charges or poles.
3. Electronics An antenna, usually fed from the center, consisting of two equal rods extending outward in a straight line.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.