murderer
noun [ C ] uk/ˈmɜː.dər.ər/ us/ˈmɝː.dɚ.ɚ/ (old-fashioned female murderess)
B1 杀人犯，凶手
someone who illegally and intentionally kills another person
A convicted murderer was executed in North Carolina yesterday. 昨天一名已定罪的杀人犯在北卡罗来纳州被处决。
a mass murderer (= someone who has killed a large number of people illegally) 杀人狂