Definition of "betray"

betray

/bɪˈtɹeɪ/

verb
third-person singular simple present betrays, present participle betraying, simple past and past participle betrayed
1. (transitive) To deliver into the hands of an enemy by treachery or fraud, in violation of trust; to give up treacherously or faithlessly.
2. (transitive) To prove faithless or treacherous to, as to a trust or one who trusts; to be false to; to deceive.
  Quotations
  I maruell I heare no nevves of Dromio, either hee ſlackes the matter, or betraies his Maiſter, I dare not motion anie thing to Stellio, till I knovv vvhat my boy hath don, Ile hunt him out, if the loiterſacke be gone ſpringing into a Tauerne, Ile fetch him reeling out.
  c. 1590 (date written), [John Lyly], Mother Bombie. […], 2nd edition, London: […] Thomas Creede, for Cuthbert Burby, published 1598, Act II, scene ii
3. (transitive) To violate the confidence of, by disclosing a secret, or that which one is bound in honor not to make known.
4. (transitive) To disclose or indicate, for example something which prudence would conceal; to reveal unintentionally.
  Quotations
  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.
  2012 May 24, Nathan Rabin, “Film: Reviews: Men In Black 3”, in The A.V. Club‎
  Again, to take a less extreme example, there is no denying that although the dialects of northern France retained their fundamentally Romance character, they betray many Germanic influences in phonetics and vocabulary, […]
  1966, Marc Léopold Benjamin Bloch, French rural history
5. (transitive) To mislead; to expose to inconvenience not foreseen; to lead into error or sin.
6. (transitive) To lead astray; to seduce (as under promise of marriage) and then abandon.