/ Dictionary / Index D deleterious: Meaning and Definition of Find definitions for: del•e•te•ri•ous Pronunciation: (del"i-tēr'ē-us), [key] — adj. injurious to health: deleterious gases. harmful; injurious: deleterious influences. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: deleterious (Thesaurus) delete deletion Related Content Daily Word Quiz: diaphanous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language