Threateningly

On the wall hung a picture of Mary, forefinger threateningly raised, looking as though she were reading the observer the riot act. "I'm in charge here!" was the inscription added beneath.

On the wall hung a picture of Mary, forefinger threateningly raised, looking as though she were in the middle of reading the viewer the riot act. Beneath read the caption: "I'm in charge here!"

The river moved slowly and threateningly.

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[.]