Source : Webster's Revised Unabridged Dictionary (1913)

Antecedency \An`te*ced"en*cy\, n.
   The state or condition of being antecedent; priority.
   --Fothherby.

Source : WordNet®

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