myocardium

noun

myo·​car·​di·​um ˌmī-ə-ˈkär-dē-əm How to pronounce myocardium (audio)
: the middle muscular layer of the heart wall
myocardial
ˌmī-ə-ˈkär-dē-əl How to pronounce myocardium (audio)
adjective

Examples of myocardium 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.
Instead, the immune system is responding to the vaccine in a way that also happens to react with heart cells in the myocardium. — Jocelyn Solis-Moreira, Popular Science, 23 Jan. 2023 When the heart is deprived of blood, ischemia – a shortage of oxygen – can damage its muscle tissue, or myocardium, reducing function and health once it is transplanted. — New Atlas, 17 Apr. 2025 Hemorrhagic softening of the myocardium, liver, kidneys and spleen. — Dawn Mitchell, Indianapolis Star, 2 Aug. 2019 Myocarditis is a rare but serious condition involving inflammation of the heart muscle, known as the myocardium. — Diana Leyva, Nashville Tennessean, 27 June 2025 Myocarditis is inflammation of the myocardium, the muscles in the heart, according to Medline Plus. — Korin Miller, Health.com, 26 Apr. 2021 During a secret operation on 8 October 1958, Senning placed the pacemaker in Arne’s abdomen wall with two leads implanted in the myocardium, a layer of muscle in the wall of the heart. — IEEE Spectrum, 28 Aug. 2025

Word History

Etymology

New Latin, from my- + Greek kardia heart — more at heart

First Known Use

1879, in the meaning defined above

Time Traveler
The first known use of myocardium was in 1879

Rhymes for myocardium

See All Rhymes for myocardium

Browse Nearby Words

myocarditis
myocardium
Myocastor
See all Nearby Words

Cite this Entry

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

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Kids Definition

myocardium

noun
myo·​car·​di·​um ˌmī-ə-ˈkärd-ē-əm How to pronounce myocardium (audio)
: the middle muscular layer of the wall of the heart

Medical Definition

myocardium

noun
myo·​car·​di·​um ˌmī-ə-ˈkärd-ē-əm How to pronounce myocardium (audio)
plural myocardia -ē-ə How to pronounce myocardium (audio)
: the middle muscular layer of the heart wall

More from Merriam-Webster on myocardium

Britannica.com: Encyclopedia article about myocardium

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