大たい量りょう殺さつ害がい

Meanings

1

mass killing; mass murder; bloodbath

Refers to the act of killing a large number of people at once, often used in news or serious contexts.

虐ぎゃく殺さつ
虐殺 emphasizes cruelty or atrocity, while 大量殺害 focuses on the scale of killing.
殺さつ人じん
殺人 is a general term for homicide or murder, not necessarily involving many victims.

Compound of 大量 (large quantity) and 殺害 (killing).