Significatio vocis merum imperium | Babel Free

Definitiones

1. The coercive, executive authority of a judge, which cannot be delegated; the right to execute criminal punishments.
   Ancient-Rome, declension-2, neuter
2. Public authority in general; the jurisdiction held and delegated by a sovereign, especially the authority over life and death; sovereignty.
   Medieval-Latin, declension-2, neuter

Exempla

“Dico⟳ merum imperium competere soli principi per excellentiam, tamen alii possunt exercere merum imperium ut presides provinciarum, multo⟳ fortius maiores iudices […]”

I say merum imperium preeminently belongs to the prince alone, but others can exercise merum imperium, such as provincial governors and much higher judges […]

Gradus CEFR