The quality or state of being emotionless, unfeeling, or capable of committing violence without remorse.
From coldblooded plus the suffix -ness, indicating a quality or state. The abstract noun form emerged to describe this character trait more formally in psychological and legal contexts.
In criminal psychology, coldbloodedness is considered a marker of certain dangerous traits—but it's important to know this is very different from the scientific term for reptiles! The metaphor stuck around even though it's biologically misleading.
Complete word intelligence in one call. Free tier — 50 lookups/day.