/ Dictionary / Index A Alzheimer's disease: Meaning and Definition of Find definitions for: Alz'hei•mer's disease" Pronunciation: (älts'hī-murz, alts'-, ôlts'-), [key] — Pathol. Pathol. a common form of dementia of unknown cause, usually beginning in late middle age, characterized by memory lapses, confusion, emotional instability, and progressive loss of mental ability. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. alyssum am Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language