The Collaborative International Dictionary of English v.0.48:

Coexistence \Co`ex*ist"ence\, n.
   Existence at the same time with another; -- contemporary
   existence.
   [1913 Webster]

         Without the help, or so much as the coexistence, of any
         condition.                               --Jer. Taylor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

coexistence
    n 1: existing peacefully together