/ Dictionary / Index S substance abuse: Meaning and Definition of Find definitions for: sub'stance abuse" Pronunciation: [key] long-term, pathological use of alcohol or drugs, characterized by daily intoxication, inability to reduce consumption, and impairment in social or occupational functioning; broadly, alcohol or drug addiction. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. substance substance P Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language