Adverb
in an alarming manner
Source: WordNetIf we were always conscious of the fact that people precious to us are frighteningly mortal, hanging not even by a thread, but by a wisp of gossamer, perhaps we would be kinder to them and more grateful for the love and friendship they give to us. Dean Koontz
Democracy 2.0.” He shudders briefly. "I'm not sure about the validity of voting projects at all, these days. The assumption that all people are of equal importance seems frighteningly obsolescent. Charles Stross
He was as alone as he had ever been, frighteningly alone, in a borderless land of shaded forests and rocky, abyssal gorges. But that was all right. He didn't much mind being alone. It was what happened when people were around that worried him. Robert Charles Wilson
Her heart was heavy because it was open, and so things filled it, and so things rushed out of it, but still the heart kept beating, tough and frighteningly powerful and meaning to shrug off the rest of her and continue on its own. Helen Oyeyemi
I'm anything but skittish about government, but I must say this administration is truly scary and, given the times we live in, frighteningly dangerous. John Dean
Frighteningly Beautiful, Dangerously Strong, Breathtakingly Fast. Face it Tally-wa you're special... Scott Westerfeld