What does diphtheria mean?
Diphtheria is an acute and highly contagious bacterial infection caused by Corynebacterium diphtheriae, which typically attacks the throat and nose. Its hallmark is a tough, grey membrane of dead tissue that spreads across the mucous membranes of the throat, potentially obstructing breathing, while a powerful toxin released by the bacteria can cause serious damage to the heart and nervous system. Historically among the most dreaded diseases of childhood, diphtheria killed large numbers of children before effective treatment emerged; its name derives from the Greek word for 'leather', a reference to that leathery throat membrane. Today, widespread vaccination with the diphtheria toxoid has made the disease rare in much of the world, though outbreaks still occur where immunisation coverage is low. The word appears chiefly in medical writing, public-health reports, and historical accounts, and it is used as an uncountable noun referring to the illness itself rather than to individual cases.
nounA serious, highly contagious bacterial infection of the throat and upper airways caused by Corynebacterium diphtheriae, producing a tough grey membrane over the mucous membranes and releasing a toxin that can damage the heart and nerves.
- An acute contagious bacterial disease affecting the throat and airways, marked by a fibrous membrane and toxin-induced complications.
"Before routine vaccination, diphtheria was one of the most feared childhood diseases."
"The doctor suspected diphtheria when she saw the grey membrane covering the child's tonsils."
"Widespread immunisation had made diphtheria so rare that many young physicians had never seen a case."
Rarely used; 'diphtheria' is normally an uncountable mass noun. A plural appears mainly in older medical texts to refer to separate cases or distinct varieties of the disease.
"The physician recorded several severe diphtherias among the children of the parish that season."
The name literally means 'leather' in Greek — after the thick grey hide-like membrane it forms across a child's throat.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of diphtheria
The word diphtheria comes from the Greek 'diphthera', meaning 'prepared hide' or 'leather', chosen for the tough, leathery membrane that forms in the patient's throat. It was coined in the early nineteenth century by the French physician Pierre Bretonneau, who gave the previously unnamed disease its modern scientific identity. The same Greek root yields the related adjectives 'diphtheritic' and 'diphtherial', used in medical descriptions of the disease and its characteristic lesions.
Related word forms
How diphtheria is actually used
Diphtheria is a formal medical term used in clinical, historical, and public-health contexts rather than everyday conversation. It functions as both a count noun ('an outbreak of diphtherias' is rare) and more commonly as an uncountable mass noun referring to the illness generally.
Easily confused with diphtheria
A diphthong is a vowel sound that glides between two positions within one syllable, whereas diphtheria is an infectious bacterial disease; they share only a similar spelling.