n. pl. u·ni·ties
a. The state or quality of being one or united into a whole: "The Founding Fathers had abhorred the concept of parties, fearing that they would undermine the unity of the nation through factionalism" (Julian E. Zelizer).
b. The state or quality of being in accord; harmony: The judges ruled in unity on the matter.
c. The state or quality of being unified in an aesthetic whole, as in a work of literature: the novel's thematic unity.
d. A whole that is a combination of parts: a group of ideas that taken together constitute a unity.
2. Singleness or constancy of purpose or action; continuity: "In an army you need unity of purpose" (Emmeline Pankhurst).
3. One of the three principles of dramatic structure derived by French neoclassicists from Aristotle's Poetics, stating that a drama should have but one plot, which should take place in a single day and be confined to a single locale.
a. The number 1.
b. See identity element.
[Middle English unite, from Old French, from Latin ūnitās, from ūnus, one; see oi-no- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus