Hexad

• POS: Noun
• HYPHEN: hex=ad

CIDE DICTIONARY

Hexad, n. [L. hexas, hexadis, the number six, Gr. , , fr. "e`x six.].

 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.  [1913 Webster]

OXFORD DICTIONARY

Hexad, n. a group of six.

Etymology

Gk hexas -ados f. hex six