betray

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To give aid or information to an enemy of; commit treason against: betray one's country.
2. v. To deliver into the hands of an enemy in violation of a trust or allegiance: betrayed Christ to the Romans.
3. v. To be false or disloyal to: betrayed their cause; betray one's better nature.
4. v. To divulge in a breach of confidence: betray a secret.
5. v. To make known unintentionally: Her hollow laugh betrayed her contempt for the idea.
6. v. To reveal against one's desire or will.
7. v. To lead astray; deceive. See Synonyms at deceive.

Century Dictionary and Cyclopedia

1. To deliver to, or expose to the power of, an enemy by treachery or disloyalty: as, an officer betrayed the city.
2. To violate by fraud or unfaithfulness; be unfaithful in keeping or upholding: as, to betray a trust.
3. To act treacherously to; be disloyal to; disappoint the hopes or expectations of.
4. To deceive; beguile; mislead; seduce.
5. To reveal or disclose in violation of confidence; make known through breach of faith or obligation: as, to betray a person's secrets or designs.
6. To show in true character; allow to be seen; permit to appear in spite of will or desire.
7. To indicate; give indication or evidence of: said of something not obvious at first view, or that would otherwise be concealed.

Wiktionary

1. v. To deliver into the hands of an enemy by treachery or fraud, in violation of trust; to give up treacherously or faithlessly; as, an officer betrayed the city.
2. v. To prove faithless or treacherous to, as to a trust or one who trusts; to be false to; to deceive; as, to betray a person or a cause.
3. v. To violate the confidence of, by disclosing a secret, or that which one is bound in honor not to make known.
4. v. To disclose or discover, as something which prudence would conceal; to reveal unintentionally; to bewray.
5. v. To mislead; to expose to inconvenience not foreseen to lead into error or sin.
6. v. To lead astray, as a maiden; to seduce (as under promise of marriage) and then abandon.
7. v. To show or to indicate; -- said of what is not obvious at first, or would otherwise be concealed.

GNU Webster's 1913

1. v. To deliver into the hands of an enemy by treachery or fraud, in violation of trust; to give up treacherously or faithlessly.
2. v. To prove faithless or treacherous to, as to a trust or one who trusts; to be false to; to deceive.
3. v. To violate the confidence of, by disclosing a secret, or that which one is bound in honor not to make known.
4. v. To disclose or discover, as something which prudence would conceal; to reveal unintentionally.
5. v. To mislead; to expose to inconvenience not foreseen to lead into error or sin.
6. v. To lead astray, as a maiden; to seduce (as under promise of marriage) and then abandon.
7. v. To show or to indicate; -- said of what is not obvious at first, or would otherwise be concealed.

WordNet 3.0

1. v. reveal unintentionally
2. v. give away information about somebody
3. v. be sexually unfaithful to one's partner in marriage
4. v. deliver to an enemy by treachery
5. v. disappoint, prove undependable to; abandon, forsake
6. v. cause someone to believe an untruth