Source : Webster's Revised Unabridged Dictionary (1913)

Coalescence \Co`a*les"cence\, n.
   The act or state of growing together, as similar parts; the
   act of uniting by natural affinity or attraction; the state
   of being united; union; concretion.

Source : WordNet®

coalescence
     n : the union of diverse things into one body or form or group;
         the growing together of parts [syn: {coalescency}, {coalition},
          {concretion}, {conglutination}]