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

valency \val"ency\, n.; pl. valencies. chem.
   a see valence.
   b a unit of combining power; a so-called bond of affinity.
       1913 webster
see also:
valencies valence 

[2] : WordNet (r) 2.0

valency
     n 1: the phenomenon of forming chemical bonds
     2: biology a relative capacity to unite or react or interact
        as with antigens or a biological substrate syn: valence
     3: chemistry a property of atoms or radicals; their combining
        power given in terms of the number of hydrogen atoms or
        the equivalent syn: valence
see also:
valence 

[3] : The Free On-line Dictionary of Computing (27 SEP 03)

valency
     
        see degree.
     
     
see also:
degree 

Valency >> V Words
Valency, definition of term: Valency
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