1. the quality or state of being fatal; the capacity to cause death or disaster

Examples

• The fatalness of the disease became apparent when the infection spread rapidly through the population.
• Doctors emphasized the fatalness of untreated sepsis in their training seminar.
• The fatalness of the accident was a shock to the entire community.
• Researchers studied the fatalness of various toxins to determine safe exposure levels.
• The fatalness of his condition meant that time was running out for treatment options.