In a way that is worrying or frightening because something seems bad or dangerous.
From 'alarm' (from Italian 'all'arme'—to arms! a battle cry) plus '-ing' (making it an adjective) plus '-ly' (making it an adverb). The word traveled from war calls to modern worry.
News headlines use 'alarmingly' to make ordinary statistics sound urgent and scary—'alarmingly high rates' might not be that extreme, but the word choice makes you panic before you read the details.
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