Pleural: Pertaining to the pleura, the thin covering that protects the lungs. The term "pleural" is pronounced like "plural" (but does not have plural meanings). SLIDESHOW Heart Disease: Causes of a Heart Attack See Slideshow From Healthy Resources 10 Rheumatoid Arthritis SymptomsWhat Is Exocrine Pancreatic Insufficiency?Truth About Vitamin B12 Featured Centers Good and Bad Foods for PsoriasisVideo: Getting Personal on Life With MS Health Solutions From Our Sponsors Shot-Free MS Treatment Your Child and COVID-19