Source : Webster's Revised Unabridged Dictionary (1913)

Richness \Rich"ness\, n.
   The quality or state of being rich (in any sense of the
   adjective).

Source : WordNet®

richness
     n 1: the property of being extremely abundant [syn: {profusion},
          {profuseness}, {cornucopia}]
     2: abundant wealth [syn: {affluence}]
     3: the property of a sound that has a rich and pleasing timbre
        [syn: {fullness}, {mellowness}]
     4: the property of producing abundantly and sustaining growth;
        "he praised the richness of the soil" [syn: {prolificacy},
         {fertility}]