/ Dictionary / Index P pericardium: Meaning and Definition of Find definitions for: per•i•car•di•um Pronunciation: (per"i-kär'dē-um), [key] — pl. -di•a the membranous sac enclosing the heart. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pericardium (Thesaurus) pericarditis pericarp Related Content Daily Word Quiz: miscreant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language