betray
1. [ verb ] reveal unintentionally
Synonyms: bewray
Examples:

"Her smile betrayed her true feelings"

Related terms: disclose
2. [ verb ] deliver to an enemy by treachery
Synonyms: sell
Examples:

"Judas sold Jesus" "The spy betrayed his country"

Related terms: deceive double_cross sell
3. [ verb ] disappoint, prove undependable to; abandon, forsake
Synonyms: fail
Examples:

"His sense of smell failed him this time" "His strength finally failed him" "His children failed him in the crisis"

Related terms: disappoint
4. [ verb ] give away information about somebody
Synonyms: tell_on rat shop grass peach shit give_away snitch stag denounce
Examples:

"He told on his classmate who had cheated on the exam"

Related terms: inform tip_off crap informer fink deserter
5. [ verb ] (sexuality) be sexually unfaithful to one's partner in marriage
Synonyms: wander cheat cuckold cheat_on
Examples:

"She cheats on her husband" "Might her husband be wandering?"

Related terms: deceive twotime play_around two-time cuckold
6. [ verb ] cause someone to believe an untruth
Synonyms: deceive lead_astray
Examples:

"The insurance company deceived me when they told me they were covering my house"

Related terms: undeceive misinform gull pose bamboozle double-crosser
Similar spelling:   beta_ray
  bettor
  better
  beater