To kill someone on the spot without being charged with murder, especially for resisting arrest, committing violence, or violating a strict prohibition.
面对敌人的猛烈进攻，守卫们接到命令，对于任何试图闯入核心区域的人，可以格杀弗论
Facing a fierce enemy assault, the guards received orders that anyone attempting to breach the core area could be executed on sight.
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