/ Dictionary / Index H hyperplasia: Meaning and Definition of Find definitions for: hy•per•pla•sia Pronunciation: (hī"pur-plā'zhu, -zhē-u, -zē-u), [key] — n. Pathol., Biol. abnormal multiplication of cells. enlargement of a part due to an abnormal numerical increase of its cells. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hyperplasia (Thesaurus) hyperplane hyperploid Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language