τῦφος

Typhoid comes from Greek τῦφος (tuphos), meaning 'smoke, vapor, stupor.' It describes the delirious, clouded mental state of fever victims.

The disease typhoid fever was named in 1829, distinguished from typhus (a different disease with similar symptoms). Both derive from the same Greek 'stupor.'

Typhoid Mary — Mary Mallon, an asymptomatic carrier who infected dozens — made 'typhoid' a metaphor for any person who spreads something harmful without showing symptoms.

The medical Greek has faded; now 'typhoid' is just a disease name, its etymology of smoky confusion forgotten.