'Myocardium' definitions:

Definition of 'myocardium'

(from WordNet)
noun
The middle muscular layer of the heart wall

Definition of 'Myocardium'

From: GCIDE
  • Myocardium \My`o*car"di*um\, n. [NL., fr. Gr. ?, ?, muscle + ? heart.] (Anat.) The main substance of the muscular wall of the heart inclosed between the epicardium and endocardium. [1913 Webster]