What does patient zero mean?

In an outbreak of an infectious disease, the term patient zero refers to the first known person to become infected with the disease.

On a related note, if you’re not sure if the word you need is patient or patience, “patient” is the adjective that often combines with “be” (e.g., “She was very patient and understanding”), while “patience” is the noun that often combines with “have” (e.g., “Do you think I have the patience to work with children?”).

Have you tried QuillBot’s free Grammar Checker? It can help you pick up errors in the use of commonly confused words such as “patient” and “patience.”