/ Dictionary / Index W Weil's disease: Meaning and Definition of Find definitions for: Weil's' disease" Pronunciation: (vīlz, wīlz), [key] a type of leptospirosis in humans, characterized by fever and jaundice, caused by the spirochete Leptospira icterohaemorrhagiae. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Weill Weimar Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language