心外膜 xīnwàimó epicardium Origin Definitions Defs Strokes Stroke Words Sentences Sents 心 xīn noun heart the physical organ that pumps blood; refers to the chest area where the heart is located外膜 wàimó outer membrane A layer of loose connective tissue forming the outermost layer of an organ, such as the heart or blood vessels; often used in contrast to the 内膜 nèimó