\Hy`per*pla"si*a\, n. [NL., fr. Gr. "ype`r over + ? conformation, fr. ? to mold.] (Med. & Biol.) An increase in, or excessive growth of, the normal elements of any part. Note: Hyperplasia relates to the formation of new elements, hypertrophy being an increase in bulk of preexisting normal elements. --Dunglison.