disease āļāļ·āļāļāļ°āđāļĢ disease āļāļ·āļāļāļ°āđāļĢ A pathological condition of a part, organ, or system of an organism resulting from various causes, such as infection, genetic defect, or environmental stress, and characterized by an identifiable group of signs or symptoms.A condition or tendency, as of society, regarded as abnormal and harmful.Obsolete Lack of ease; trouble.