/ Dictionary / Index A adverse possession: Meaning and Definition of Find definitions for: adverse' posses'sion Pronunciation: [key] — Law. Law. the open and exclusive occupation and use of someone else's real property without permission of the owner continuously for a period of years prescribed by law, thereafter giving title to the occupier-user. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. adverse adverse selection Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language