In a blank manner, especially showing no emotion or expression (adverb)
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Use "blankly" in a sentence
"Mr. Campion repeated the name blankly but as recollection came to him his eyes widened."
"I love that boy dearly, but when he's not-entirely-sober, he tends to spend large amounts of time staring at me somewhat blankly, which is really unnerving when I'm trying to concentrate on something else, particularly if it's something like writing, where I have to use a different portion of my brain than I do for photoshopping, or reading something, as far as I can tell."
"The desire in his eyes cracked into a thousand pieces like the shards of the Portal mirror at Renwick’s, and for a moment his expression was blankly astonished."