Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary


combining form

Definition of tri-

  1. 1 :  three :  having three elements or parts <trigraph>

  2. 2 :  into three <trisect>

  3. 3a :  thrice <triweekly>b :  every third <trimonthly>

Origin and Etymology of tri-

Latin (from tri-, tres) & Greek, from tri-, treis — more at three

Seen and Heard

What made you want to look up tri-? Please tell us where you read or heard it (including the quote, if possible).