Ominously

Full definition of ominously

Adverb

1. in an ominous manner; with sinister foreboding
• 1868, Wilkie Collins, The Moonstone‎From first to last he was ominously polite, and ominously silent.
• 1983, Patricia Hagan, Golden RosesHis nostrils flared ominously and his fists opened and closed at his sides.