In a manner that is marked by dread, fear, or apprehension; with a fearful or anxious quality.
From dread + -ing (present participle) + -ly (adverbial suffix). The -ing form captures the ongoing state of fearing, modified by -ly to describe how an action is performed.
This word is rare because English speakers usually prefer 'dreading' or 'dreadfully' instead—but 'dreadingly' specifically means doing something while actively feeling dread, like approaching something with mounting fear.
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