The Collaborative International Dictionary of English v.0.48:
Massacre \Mas"sa*cre\, v. t. [imp. & p. p. Massacred; p. pr. &
vb. n. Massacring.] [Cf. F. 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.