Webster's Revised Unabridged Dictionary · 1913

Massacre

Massacre , noun

[French, from Late Latin mazacrium; compare Prov. German metzgern, metzgen, to kill cattle, German metzger a butcher, and LG. matsken to cut, hew, Old High German meizan to cut, Gothic máitan.]

1.
The killing of a considerable number of human beings under circumstances of atrocity or cruelty, or contrary to the usages of civilized people; as, the massacre on St. Bartholomew's Day; the St. Valentine's Day massacre; the Amritsar massacre; the Wounded Knee massacre.
2.
Murder. [Obsolete] — Shakespeare
I'll find a day to massacre them all, And raze their faction and their family. — Shakespeare
If thou delight to view thy heinous deeds, Brhold this pattern of thy butcheries. — Shakespeare
Such a scent I draw Of carnage, prey innumerable! — Milton

Massacre , transitive verb

[Compare French massacrer. See Massacre, n.]

To kill in considerable numbers where much resistance can not be made; to kill with indiscriminate violence, without necessity, and contrary to the usages of nations; to butcher; to slaughter; -- limited to the killing of human beings.
If James should be pleased to massacre them all, as Maximian had massacred the Theban legion. — Macaulay