patient zero

noun
plural patient zeros also patient zeroes

Definition of patient zero

: a person identified as the first to become infected with an illness or disease in an outbreak The quest to find patient zero, the first person to contract the new virus, has revealed the first known case occurred in Wuhan …— Susan Dunlevy especially : a person documented as being the first known case of a communicable disease in a particular population or region Stay out of hospital emergency rooms unless you are severely ill or injured. For now, it's the likeliest place to catch coronavirus. Anyone unknowingly suffering from coronavirus is likely to go there. That's what "patient zero" in Italy did. — Betsy McCaughey The 26-year-old nurse contracted Ebola after volunteering to care for U.S. 'patient zero' Thomas Eric Duncan, who tragically died on October 10 from the deadly disease. — Ashley Collman et al. — compare index case sense 2

First Known Use of patient zero

1987, in the meaning defined above

Keep scrolling for more

Learn More about patient zero

Time Traveler for patient zero

Time Traveler

The first known use of patient zero was in 1987

See more words from the same year

Statistics for patient zero

Cite this Entry

“Patient zero.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/patient%20zero. Accessed 16 Apr. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Comments on patient zero

What made you want to look up patient zero? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

Test Your Vocabulary

The Exceptions Quiz III

  • one green toy robot amidst many red toy robots
  • Which of these words does not mean "nonsense"?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!