darkly
adv.adv. in a way that is serious, mysterious, or slightly scary. You use this to describe a person's mood or a story that has a serious and gloomy feeling.
adv. in a manner that is serious, somber, or ominous; in a way that suggests a lack of light or a mysterious atmosphere.
He spoke darkly about the future of the company.
The author wrote the ending darkly, leaving the reader with a sense of unease and foreboding.
The protagonist's darkly humorous observations about the political landscape reveal a deep-seated cynicism that he has developed over decades of service.
From Middle English derkly, derkely, derkliche, derkeliche; equivalent to dark + -ly. Compare Old English deorclīċe, a parallel formation.
From Middle English derkely, equivalent to dark + -ly.