Lassitude: Weakness, weariness, listlessness, exhaustion, lethargy. For example, the patient complained of lassitude. From Latin lassitudo, from lassus meaning weary. From Healthy Resources 10 Rheumatoid Arthritis SymptomsWhat Is Exocrine Pancreatic Insufficiency?Life With RRMS: A Shift in Positivity Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew Health Solutions From Our Sponsors