Antecedency \An`te*ced"en*cy\, n.
   The state or condition of being antecedent; priority.
   --Fothherby.
   [1913 Webster]
Source: The Collaborative International Dictionary of English

antecedency
     n : preceding in time [syn: {priority}, {antecedence}, {anteriority},
          {precedence}, {precedency}] [ant: {posteriority}]
Source: WordNet® 2.0