1. Relating to or having two poles or charges.
2. Relating to a device capable of using two polarizations, such as a transistor that uses positive and negative charge carriers.
3. Relating to or involving both of the earth's polar regions.
4. Having two opposite or contradictory ideas or natures: the bipolar world of the postwar period.
5. Biology Having two poles or opposite extremities: a bipolar neuron.
6. Psychiatry Of, relating to, or having bipolar disorder.
Informal A person with bipolar disorder.
bi′po·lari·ty (-lărĭ-tē) n.
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.