Definition of "double-cross" [double-cross]

• To betray by acting in contradiction to a prior agreement. See Synonyms at deceive. (verb-transitive)
• An act of betraying an ally, a friend, or an associate. (noun)
• Genetics A cross in which each parent is the product of a single cross. It can be represented as AB × CD, where A, B, C, and D are inbred lines. (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.

• "Okay, we lost grandma to cancer because the Blue Cross was more of a double-cross when they told us she'd cost them enough and they weren't paying more, but at least Barack Husein Obama didn't make her shovel-ready."
• "TCM has two of the best: Double Indemnity (tonight, 8 ET/5 PT), a seminal double-cross film noir starring Barbara Stanwyck and Fred MacMurray (in a far cry from his My Three Sons days); and Swing Time (10 ET/7 PT), which may just be the best of the Fred Astaire/Ginger Rogers films, and is the only one to address hard economic times."
• "Once again, this struck the natives as the worst kind of double-cross."