Leaden/ˈledn/ Definition 1 of 2Pro Tip 1/3Physical Fatigue Used to describe the weight and slowness caused by tiredness or physical burden. His limbs felt leaden after the marathon. Pro Tip 2/3Emotional State Expresses the sluggish movements due to a person's sadness or despair. Her heart felt leaden with grief. Pro Tip 3/3Atmosphere Conveys a mood or atmosphere that is dull and lacking in energy. The party was leaden, with few people dancing.