Phrase guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
No pronunciation record was provided for this word.
noun
The initial patient in the population of an epidemiological investigation.
Definition source: English Wiktionary via Wiktextract
Topics: epidemiology, medicine, sciences
No example sentence was provided for this meaning.
Synonyms: index patient
Antonyms: none provided
Broader terms: patient
noun
The source or origin of something.
Definition source: English Wiktionary via Wiktextract
Usage: figuratively, informal
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
History
Originally patient O (standing for out of California), referring to Gaëtan Dugas, a superspreader of AIDS who was at the time erroneously believed to have introduced the virus to the United States. The letter O was later misinterpreted as a zero.
