tri-

Three.

Used for the digit three to form systematic element names of elements whose existence has been predicted, and which have not yet been given a trivial name.

un- (“1”) + bi- (“2”) + tri- (“3”) + -ium (element suffix) → unbitrium (“element 123”)

Used in combination with a known element name (e.g. 'tri-silicon', 'tri-lead') 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 elemen