Heptavalent
Pronunciation : Hep*tav"a*lent
Part of Speech : a.
Etymology : [Hepta- + L. valens, p. pr. See Valence.] (Chem.)
Definition : Defn: Having seven units of attractive force or affinity; -- said of heptad elements or radicals.
Source : Webster's Unabridged Dictionary, 1913