infectious disease
noun
- a disease (such as influenza, malaria, meningitis, rabies, or tetanus) caused by the entrance into the body of pathogenic agents or microorganisms (such as bacteria, viruses, protozoans, or fungi) which grow and multiply there
- (in plural) the medical specialty focused on the diagnosis, treatment, and prevention of infectious diseases
Wiktionary
noun
- An illness caused by a specific infectious agent (bacterium, virus, fungus, protozoa, prion etc.), that results from transmission of that agent from an infected person, animal, or reservoir to a susceptible host.
- A medical specialty dealing with the diagnosis, control and treatment of infections.