n.
Pronunciation: - ' kär-d ē - ə m
Function: noun
Inflected Form: plural -dia \ -d ē - ə \
Etymology: Middle English, from Medieval Latin, from Greek perikardion, neuter of perikardios around the heart, from peri- + kardia heart ― more at HEART
Date: 15th century
1 : the conical sac of serous membrane that encloses the heart and the roots of the great blood vessels of vertebrates
2 : a cavity or space that contains the heart of an invertebrate and in arthropods is a part of the hemocoel