threateningly

adv

1. In a threatening manner.

   “He tried to glare threateningly, but how much of a threat can you be when you are naked AND tied to a bed?”

   “As the beasts surrounded her, chattering threateningly the while they goaded her with their cudgels and beat and kicked her with their fists and feet, she lay with closed eyes, praying for the merciful death that she knew alone could give her surcease from suffering[.]”