patient zero

[ pey-shuhnt zeer-oh ]

  1. Pathology. the first known carrier of infection in an outbreak: Public health officials are tracing all contacts of infected patients, trying to work their way back to find patient zero.: See also index patient.

  2. the person or thing that is believed to be the point of origin for any spreading effect, status, or event, especially if negative: One rowdy new student was patient zero for all kinds of classroom chaos and problem behaviors.

Origin of patient zero

First recorded in 1985–90

Words Nearby patient zero Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024