Bipolar

having two poles, as the earth.
of, relating to, or found at both polar regions.
characterized by opposite extremes, as two conflicting political philosophies.
Electronics. of or relating to a transistor that uses both positive and negative charge carriers.
Psychiatry. of, relating to, or having bipolar disorder:
His wife is bipolar.
Contemporary Examples

Sandusky Lawyer Reveals Appeal Plan Diane Dimond October 10, 2012
Silver Linings Playbook’s Silver Lining–Honest Talk About Mental Illness Michelle Raimo Kouyate, Renee Witt February 17, 2013
‘Homeland’ Showrunner: ‘We Knew We Had to Plot a New Course’ Andrew Romano September 29, 2013
James McAvoy on ‘Filth,’ His Wild Bachelor Party, and BB Gun Fights with Jennifer Lawrence Marlow Stern May 20, 2014
Mother’s Little Anti-Psychotic Is Worth $6.9 Billion A Year Jay Michaelson November 8, 2014

Historical Examples

Essays, Second Series Ralph Waldo Emerson
History of the Intellectual Development of Europe, Volume II (of 2) John William Draper
The Mechanism of Life Stphane Leduc
Astronomy David Todd
Astronomy David Todd

adjective
having two poles: a bipolar dynamo, a bipolar neuron
relating to or found at the North and South Poles
having or characterized by two opposed opinions, natures, etc
(of a transistor) utilizing both majority and minority charge carriers
suffering from bipolar manic-depressive disorder
adj.

bi’po·lar’i·ty (-lār’ĭ-tē) n.
bipolar
(bī-pō’lər)