Definition of Tri-
1. Prefix. three ¹
2. Prefix. (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. ¹
¹ Source: wiktionary.com
Medical Definition of Tri-
1. A prefix meaning three, thrice, threefold; as in tricoloured, tridentate.
2. 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.
Origin: Gr. Tri- or L. Tri-, sometimes through French; akin to L. Tres three, and E. Three. See Three.
(29 Oct 1998)
Lexicographical Neighbors of Tri-