noun
Refers to the act of killing a king; a straightforward compound noun. Compare with 王殺し, which can refer to killing any monarch or a king in a broader sense.
See also: 王殺し
国王殺しは大逆罪とされた。
Regicide was considered high treason.
More general term for killing a monarch; 国王殺し specifically refers to killing a king.
Compound of 国王 (king) and 殺し (killing), from the verb 殺す (to kill).