Late Latin hexashexad-the number sixfrom Greek fromhexsixs(w)eks in Indo-European roots
American Heritage Dictionary of the English Language, 5th Edition
Hexad Sentence Examples
Mapping the hexad corresponding to 23 with these elements yields the corresponding hexads.
Those elements which are equivalent in combining or displacing power to a single atom of hydrogen are said to be univalent or monad elements; whilst those which are equivalent to two atoms of hydrogen are termed bivalent or dyad elements; and those equivalent to three, four, five or six atoms of hydrogen triad, tetrad, pentad or hexad elements.
Again, when tungsten hexachloride is converted into vapour it is decomposed into chlorine and a pentachloride, having a normal vapour density, but as in the majority of its compounds tungsten acts as a hexad, we apparently must regard its pentachloride as a compound in which an odd number of free affinities are disengaged.