/ Dictionary / Index P preventive: Meaning and Definition of Find definitions for: pre•ven•tive Pronunciation: (pri-ven'tiv), [key] — adj. of or noting a drug, vaccine, etc., for preventing disease; prophylactic. serving to prevent or hinder: preventive measures. —n. a drug or other substance for preventing disease. a preventive agent or measure. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: preventive (Thesaurus) prevention preventive detention Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language