- A close association of nations or other groups, formed to advance common interests or causes: an alliance of labor unions opposing the bill. (noun)
- A formal agreement establishing such an association, especially an international treaty of friendship. (noun)
- A connection based on kinship, marriage, or common interest; a bond or tie: the shifting alliances within a large family. (noun)
- Close similarity in nature or type; affinity: the ancient alliance between mathematics and music. (noun)
- The act of becoming allied or the condition of being allied: the church, acting in alliance with community groups. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.