Tri- (?). [Gr. tri- or L. tri-, sometimes through French; akin to L. tres three, and E. three. See Three.]
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1. A prefix meaning three, thrice, threefold; as in tricolored, tridentate.
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2. (Chem.) A prefix (also used adjectively) denoting three proportional or combining part, or the third degree of that to the name of which it is prefixed; as in trisulphide, trioxide, trichloride.
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