D defs.my
Entry 1 sense Webster, 1913

Hexad

· Hex·ad · IPA /ˈhɛksæd/
01 n. An atom whose valence is six, and which can be theoretically combined with, substituted for, or replaced by, six monad atoms or radicals; a…
  1. 1.
    An atom whose valence is six, and which can be theoretically combined with, substituted for, or replaced by, six monad atoms or radicals; as, sulphur is a hexad in sulphuric acid. Also used as an adjective.(chem.)