Coronavirus and the New Words We Added to the Dictionary in March 2020

New words from the COVID-19 pandemic

Find the latest list of words added to the dictionary here

A dictionary’s mission is to give accurate information about the current vocabulary of a language. Providing precise definitions, usage information, dates, etymologies, and pronunciations takes time; typically, additions to our dictionary occur in large batches a few times each year as our staff completes the various tasks required for each new entry or revision.

Because the COVID-19 crisis has developed at such a rapid pace and some of the words and ideas associated with the crisis are themselves new, we have made an unscheduled update for words connected with the disease and responses to it. Some of these terms are new to the dictionary, others have revised definitions. Some words are newly prominent in the language, qualifying for entry in record time, while others had previously been scheduled for entry in the near future.


Among the new terms are 'social distancing,' 'super-spreader,' and 'index case.'

Naming the Disease

  • COVID-19 is a new name for a new disease, coined as an abbreviated form of coronavirus disease 2019.
  • Coronavirus is the broader name for the family of viruses that includes COVID-19, and its entry has been revised to show that relationship. A new example has been added to the entry for novel (“new”).

Important Abbreviations

  • SARS (“severe acute respiratory syndrome”) and MERS (“Middle East respiratory syndrome”) were already dictionary entries as was the abbreviation for coronavirus, CoV, but we have added the more technical designations SARS-CoV, SARS-CoV-2, and MERS-CoV.
  • A new entry has also been added for the abbreviation for “novel coronavirus,” nCoV.


  • Index case is defined as the first documented case of an infectious disease or genetically transmitted condition or mutation in a population, region, or family.
  • Index patient is defined as an individual affected with the first known case of an infectious disease or genetically transmitted condition or mutation in a population, region, or family.
  • Patient zero is defined as a person identified as the first to become infected with an illness or disease in an outbreak.
  • Contact tracing means the practice of identifying and monitoring individuals who may have had contact with an infectious person as a means of controlling the spread of a communicable disease.
  • Community spread refers to the spread of a contagious disease to individuals in a particular geographic location who have no known contact with other infected individuals or who have not recently traveled to an area where the disease has any documented cases.
  • Super-spreader and its related noun super-spreading refer to an individual who is highly contagious and capable of transmitting a communicable disease to an unusually large number of uninfected individuals.


  • Social distancing is a new term for most of us, but has become ubiquitous in coverage of safe practices for preventing the spread of the disease. A new definition has been added to social distance and the verb socially distance has also been added.
  • Self-quarantine means to refrain from any contact with other individuals for a period of time (such as two weeks) during the outbreak of a contagious disease usually by remaining in one's home and limiting contact with family members.