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1. The quality of being unresponsive; not reacting; as a quality of people, it is marked by a failure to respond quickly or with emotion to people or events
   "in an instant all the deadness and withdrawal were wiped away";
   - unresponsiveness
    
2. The physical property of something that has lost its elasticity
   "he objected to the deadness of the tennis balls"
    
3. The inanimate property of something that has died

Type of: inanimateness, inelasticity, lifelessness, quality

Antonym: responsiveness

Encyclopedia: Deadness