I actually had to look up the definition of Martial Law

Martial law involves the temporary substitution of military authority for civilian rule and is usually invoked in time of war, rebellion, or natural disaster. When martial law is in effect, the military commander of an area or country has unlimited authority to make and enforce laws.

SEOUL, Dec 3 (Reuters) - South Korean President Yoon Suk Yeol on Tuesday declared martial law in a surprise late-night TV address, slamming domestic political opponents and sending shockwaves through the country. Yoon said opposition parties had taken the parliamentary process hostage. He vowed to eradicate "shameless pro-North Korean anti-state forces" and said he had no choice but to take the measure to safeguard constitutional order.

I actually had to look up the definition of Martial Law

Martial law involves the temporary substitution of military authority for civilian rule and is usually invoked in time of war, rebellion, or natural disaster. When martial law is in effect, the military commander of an area or country has unlimited authority to make and enforce laws.