/ Dictionary / Index L life-threatening: Meaning and Definition of Find definitions for: life-threat•en•ing Pronunciation: (līf'thret"ning, -thret"n-ing), [key] — adj. endangering life: a life-threatening illness. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: life-threatening (Thesaurus) life table lifetime 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