Pentad

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Pentad \Pen"tad\, n. [Gr. penta`s penta`dos, a body of five, fr.
     pe`nte five.] (Chem.)
     Any element, atom, or radical, having a valence of five, or
     which can be combined with, substituted for, or compared
     with, five atoms of hydrogen or other monad; as, nitrogen is
     a pentad in the ammonium compounds.


     [1913 Webster]
  
     2. Any grouping of five things.
        [PJC]

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Pentad \Pen"tad\, a. (Chem.)
     Having the valence of a pentad.
     [1913 Webster] Pentadactyl

From WordNet (r) 2.0 [wn]:

  pentad
       n : the cardinal number that is the sum of four and one [syn: {five},
            {5}, {V}, {cinque}, {quint}, {quintet}, {fivesome}, {quintuplet},
            {fin}, {Phoebe}, {Little Phoebe}]