diphtheria

noun

diph·​the·​ria dif-ˈthir-ē-ə How to pronounce diphtheria (audio)
nonstandard
dip- How to pronounce diphtheria (audio)
: an acute febrile contagious disease typically marked by the formation of a false membrane especially in the throat and caused by a gram-positive bacterium (Corynebacterium diphtheriae) that produces a toxin causing inflammation of the heart and nervous system
diphtherial
dif-ˈthir-ē-əl How to pronounce diphtheria (audio)
nonstandard dip-
adjective
diphtheritic
ˌdif-thə-ˈri-tik How to pronounce diphtheria (audio)
nonstandard ˌdip-
adjective

Examples of diphtheria in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Pursued by legendary lawman Pat Garrett and his ambitious young deputy, Ross takes refuge at a remote homestead ravaged by diphtheria. — Brian Welk, IndieWire, 13 May 2026 Adolescents should then receive a Tdap or tetanus, diphtheria and acellular pertussis booster at age 11 or 12. — Faye Chiu, CNN Money, 23 June 2026 His and Isabel’s first two children both died of diphtheria in March, 1865, just weeks before President Lincoln’s death. — Sebastian Smee, New Yorker, 4 May 2026 In addition, research has shown the shingles vaccine is associated with a lower dementia risk than the influenza and Tdap (tetanus-diphtheria-pertussis) vaccines. — Lindsey Leake, NBC news, 28 June 2026 See All Example Sentences for diphtheria

Word History

Etymology

New Latin, from French diphthérie, from Greek diphthera leather; from the toughness of the false membrane

First Known Use

circa 1851, in the meaning defined above

Time Traveler
The first known use of diphtheria was circa 1851

Rhymes for diphtheria

See All Rhymes for diphtheria

Browse Nearby Words

diphosphothiamine
diphtheria
diphtheroid
See all Nearby Words

Cite this Entry

“Diphtheria.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diphtheria. Accessed 7 Jul. 2026.

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Kids Definition

diphtheria

noun
diph·​the·​ria dif-ˈthir-ē-ə How to pronounce diphtheria (audio) dip- How to pronounce diphtheria (audio)
: a contagious bacterial disease with fever in which the air passages become coated with a membranous layer that often obstructs breathing
diphtheritic
ˌdif-thə-ˈrit-ik How to pronounce diphtheria (audio)
ˌdip-
adjective

Medical Definition

diphtheria

noun
diph·​the·​ria dif-ˈthir-ē-ə How to pronounce diphtheria (audio) dip- How to pronounce diphtheria (audio)
: an acute febrile contagious disease typically marked by the formation of a false membrane especially in the throat and caused by a bacterium of the genus Corynebacterium (C. diphtheriae) which produces a toxin causing inflammation of the heart and nervous system
diphtherial
-ē-əl How to pronounce diphtheria (audio)
adjective

More from Merriam-Webster on diphtheria

Nglish: Translation of diphtheria for Spanish Speakers

Britannica.com: Encyclopedia article about diphtheria

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