Source : Webster's Revised Unabridged Dictionary (1913)

Neoplasia \Ne`o*pla"si*a\, n. [NL., fr. gr. ? new + ? to form,
   mold.] (Physiol. & Med.)
   Growth or development of new material; neoplasty.

Source : WordNet®

neoplasia
     n : the pathological process that results in the formation and
         growth of a tumor