The distance between the outstretched tips of the little finger and thumb when used as a unit of measurement(noun)
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Use "handspan" in a sentence
"Shaking his head, Vincent straightened and stepped away from the Jaguar to stand less than a handspan from Dante."
"Only a scant handspan separated their bodies, almost as if she had sought to get as close to him as she dared without actually touching him."
"The blanket was down by our feet, and I was really aware of him next to me, without a sheet or blanket covering us, his bare legs just a handspan away from mine."