disease Definition

1. A lack of health, a disorder or illness caused by infection rather than by an accident.

Thesaurus: illness, sickness, infirmity, infection, contamination; Antonym: health, wellness.
2. Any one such illness with characteristic symptoms.

Example: immunization against diseases such as measles
Thesaurus: illness, sickness, ailment, malady, disorder, complaint, malaise, infirmity; infection, contamination, plague, germ, virus.
3. Any undesirable phenomenon.

Example: the social disease of drug addiction