American Heritage® Dictionary of the English Language, Fourth Edition
- Three: trilobate.
- Occurring at intervals of three: trimonthly.
- Occurring three times during: triweekly.
Century Dictionary and Cyclopedia
- n. Specifically, in chem., a prefix to the names of compounds containing three atoms or combining units of some particular element or radical, as sulphur trioxid, SO3, and triethylamine, N(C2H5)3.
- n. A prefix of Latin and Greek origin, meaning ‘three.’
- chemistry Used in combination with a known element name (e.g. 'tri-silicon') to designate an unknown element that would reside three periods lower than the known element on a Mendeleev-type periodic table. See Mendeleev's predicted elements.
GNU Webster's 1913
- A prefix meaning
three, thrice, threefold; as in tricolored, tridentate.
- (Chem.) A prefix (also used adjectively) denoting
three proportional or combining part, or the third degreeof that to the name of which it is prefixed; as in trisulphide, trioxide, trichloride.
- From Sanskrit (tri-, "three"). (Wiktionary)
- Middle English, from Latin and Greek; see trei- in Indo-European roots. (American Heritage® Dictionary of the English Language, Fourth Edition)
“I think it's extremely important that whatever follows the MDGs moves beyond a list of non-binding, broad objectives, and that any targets agreed are better linked to binding international bi- tri- and multilateral agreements.”
“The aroma of asafoetida is due to a complex mixture of sulfur compounds, a dozen identical with volatiles in the onion family, and a number of less common di-, tri-, and tetrasulfides.”
‘tri-’ hasn't been added to any lists yet.
Looking for tweets for tri-.