Tri-
Tri-
[Greek tri- or Latin tri-, sometimes through French; akin to Latin tres three, and English three. See Three.]
1.
A prefix meaning three, thrice, threefold; as in tricolored, tridentate.
2.
(Chemistry) 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.