Violation of allegiance toward one's country or sovereign, especially the betrayal of one's country by waging war against it or by consciously and purposely acting to aid its enemies.
A betrayal of trust or confidence.
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.