octad

from WordNet (r) 3.0 (2006)

octad
    n 1: the cardinal number that is the sum of seven and one [syn:
         {eight}, {8}, {VIII}, {eighter}, {eighter from Decatur},
         {octad}, {ogdoad}, {octonary}, {octet}]

from The Collaborative International Dictionary of English v.0.48

Octad \Oc"tad\, n. [Gr. ?, ?, the number eight.]
   1. (Chem.) An atom or radical which has a valence of eight,
      or is octavalent.
      [1913 Webster]

   2. A group of eight things.
      [PJC]

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