myocardium

From New Latin myocardium, from Ancient Greek μῦς (mûs, “muscle”) + καρδίᾱ (kardíā, “heart”).

myocardium (plural myocardiums or myocardia)

1. (anatomy, cardiology) The muscular substance of the heart; the middle of the three layers forming the outer wall of the human heart.

• (muscular substance of the heart): cardiac muscle, heart muscle

• (muscular substance of the heart): muscle

• “myocardium”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “myocardium”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.
• cardiac muscle on Wikipedia.Wikipedia

• (Classical) IPA^(key): /my.oˈkar.di.um/, [myɔˈkärd̪iʊ̃ˑ]
• (modern Italianate Ecclesiastical) IPA^(key): /mi.oˈkar.di.um/, [mioˈkärd̪ium]

myocardium n (genitive myocardiī or myocardī); second declension

1. myocardium
2. muscular substance of the heart

Second-declension noun (neuter).

¹Found in older Latin (until the Augustan Age).