Definition of "jinx"

jinx

/d͡ʒɪŋks/

noun
plural jinxes
1. A hex; an evil spell.
2. A person or thing supposed to bring bad luck.
verb
third-person singular simple present jinxes, present participle jinxing, simple past and past participle jinxed
1. (transitive) To cast a spell on.
2. (transitive) To bring bad luck to.
3. (transitive) To cause something to happen by mentioning it, usually sarcastically.
  Quotations
  “So you'll all be near New York!” Maggie says. “We don't know for sure yet.” Sara stresses. “Don't jinx it.”
  2008, Susane Colasanti, chapter 46, in When It Happens‎, Penguin
  I've no idea if she guessed what I was intending to do. I don't know why I was so reluctant to talk about it, even to her. Maybe I was afraid that verbalising my intentions would jinx it in some way.
  2012, Sally Heinrich, Hungry Ghosts, Hachette UK
interjection
1. Used after the same thing is said by two people simultaneously.
  Quotations
  Bart: I'm telling Mom and Dad! / Lisa: You're telling who? / Bart: Mom and Dad! / Girls: MOM AND DAD? JINX! / Janey Powell: Now you can't talk, 'til somebody says your name!
  1991, Robert Cohen, “Flaming Moe's”, in The Simpsons‎, season 3, episode 10 (television production)