Source : Webster's Revised Unabridged Dictionary (1913)

Coexistent \Co`ex*ist"ent\, a.
   Existing at the same time with another. -- n. That which
   coexists with another.

         The law of coexistent vibrations.        --Whewell.

Source : WordNet®

coexistent
     adj : existing at the same time [syn: {coexisting}]