betray

verb

Etymology: From Middle English betrayen, bitrayen (“to commit an act of treason against”), equivalent to be- + tray (“to betray”). Middle English bi- is from Old English be- (“be-”), from Proto-Germanic *bi- (“be-”), from Proto-Germanic *bi (“near, by”), ultimately from Proto-Indo-European *h₁epi (“at, near”). Compare also traitor, treason, tradition. The modern sense “to disclose, discover, reveal unintentionally” is due to influence from or merger with English bewray (“to reveal, divulge”), which is similar in sound and meaning. The similarity with German betrügen, Dutch bedriegen, from Proto-West Germanic *bidreugan (“to betray, deceive”), is coincidental.

1. To deliver into the hands of an enemy by treachery or fraud, in violation of trust; to give up treacherously or faithlessly.

   “An officer betrayed the city.”

   “He betrayed his own sister to the secret police.”

2. To prove faithless or treacherous to, as to a trust or one who trusts; to be false to; to deceive.

   “to betray a person or a cause”

   “Quresh betrayed Sunil to marry Nuzhat.”

3. To violate the confidence of, by disclosing a secret, or that which one is bound in honor not to make known.
4. To disclose (a secret, etc.) in deliberate violation of someone’s confidence.

   “The dead leap at the throat, destroy The meaning of the day; dark forms Have scaled your walls, and spies betray Old secrets to amorphous swarms.”

5. To disclose or indicate, for example something which prudence would conceal; to reveal unintentionally.

   “Though he had lived in England for many years, a faint accent betrayed his Swedish origin.”

   “Jones’ sad eyes betray a pervasive pain his purposefully spare dialogue only hints at, while the perfectly cast [Josh] Brolin conveys hints of playfulness and warmth while staying true to the craggy stoicism at the character’s core.”

6. To mislead; to expose to inconvenience not foreseen; to lead into error or sin.
7. To lead astray; to seduce (as under promise of marriage) and then abandon.