COVID-19 Glossary

Browse the glossary using this index

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ALL

Page: (Previous)   1  2  3  4  5  6  7  8  (Next)


incubation period

The amount of time it takes for an infected person to start showing symptoms. Most people develop COVID-19 symptoms by day 12, but some people will take longer.

index case

The first documented case of an infectious disease or genetically transmitted condition or mutation in a population, region, or family. It may also refer to an individual who has a disease, condition, or mutation that is the first one identified in a population. This second sense is synonymous with index patient. A related term is patient zero, “a person identified as the first to become infected with an illness or disease in an outbreak.” Patient zero is especially used to refer to a person documented as being the first known case of a communicable disease in a particular population or region.


Producing or capable of producing infection, containing pathogenic agents which may be transmitted. 

An ailment such as food poisoning is infectious, it is capable of producing infection, but it is not contagious. The coronavirus, on the other hand, is both contagious and _infectious. Anything that is contagious is automatically also infectious, but the reverse is not true. Both words are frequently used in a figurative manner.


When a person who is showing symptoms of a disease separates themselves from other people to prevent spreading the disease to others.


lab-confirmed case

When a person is diagnosed with a disease that is confirmed through having specimens (samples) tested in a laboratory.


martial law

The law administered by military forces that is invoked by a government in an emergency when the civilian law enforcement agencies are unable to maintain public order and safety. 

The martial portion of martial law comes from the Latin word martalis, meaning “of Mars” (referring to the Roman god of war).


Middle East Respiratory Syndrome. Another type of coronavirus, transmitted from camels. MERS is more deadly than COVID-19. It causes noticeable symptoms in most people, so it’s easier to track the virus.

morbidity rate

The number of people who will get sick from a particular cause in a particular population over a certain period of time. To calculate the morbidity rate you would divide the number of sick people in a population by the number of healthy people.

mortality rate

The number of deaths from a particular cause in a particular population over a certain period of time. To calculate the mortality rate, you would divide the number of deaths by the number of sick and healthy people in a population.


N95 respirator (face mask)

Personal protective equipment that is used to protect the wearer from airborne particles and from liquid contaminating the face.

negative-pressure rooms

Rooms specifically designed for patients with contagious diseases that contain any circulating air in the room and prevent it from being released into any other part of the hospital.

novel coronavirus (nCoV)

Any new coronavirus that hasn’t been studied yet or that has just emerged. When SARS-CoV-2 was first found, it was called 2019-nCoV. The SARS-CoV-2 virus causes the disease, which is called COVID-19.



An outbreak is when a disease spreads quickly in a group of people (or animals or plants or …) in one place at one time. When a bunch of people in one town get food poisoning, that’s an outbreak. An epidemic is a really big outbreak, but still just one place at one time.



A global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread easily between people.


Stands for Powered Air-Purifying Respirator. They’re the giant full-body suits and helmets healthcare workers wear to treat people quarantined with infectious diseases.

Page: (Previous)   1  2  3  4  5  6  7  8  (Next)