offensive. Usually with capital initial. A member of the Nizari sect of the Ismaili branch of Islam, which was founded by Ḥasan-e Ṣabbāḥ in the…

(A name given to) Ḥasan-e Ṣabbāḥ (d. 1124), founder of the Assassins, who established a base for the sect at Alamut, a mountain fortress near Qazvin…

Originally: an Ismaili Muslim assassin (cf. assassin, n. 1). Later also: a dedicated killer in the same tradition. Now historical.

Usually with capital initial. A member of a society or cult of robbers and murderers in India known for strangling their victims; = Phansigar, n. Cf…

the person in a gang of criminals responsible for the physical assault of a victim.

A serial killer, a brutal murderer; (in extended use) a merciless or unscrupulous person.

colloquial. A murderer who rips and mutilates the bodies of his or her victims; frequently (with the and capital initial) in the popular names of…

a murderer who sexually assaults his or her victim(s).

= serial killer, n.

A psychopathic killer, esp. as represented in films or popular fiction.

A person who commits a series of murders, often with no apparent motive and typically following a characteristic behaviour pattern. Cf. spree killer…

a person who kills in a frenzied, random, apparently unpremeditated manner with no obvious motive; spec. one who kills a number of people at one…