The quality or state of not being accustomed.(noun)
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Use "unaccustomedness" in a sentence
"But her country unaccustomedness to conversation held her tongue-tied for a time."
"She had thought it was his shyness, his unaccustomedness to women that had made him such a failure as a lover -- and all the while it had been simply that she was not the right woman."
"He was a large, heavy, pale-faced young man, with strange, sleek qualities that appealed to her through their unaccustomedness."