/ Dictionary / Index I illness: Meaning and Definition of Find definitions for: ill•ness Pronunciation: (il'nis), [key] — n. unhealthy condition; poor health; indisposition; sickness. wickedness. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: illness (Thesaurus) ill-natured illocutionary Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language