Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
nicety, niceness (nn.)
These nouns are not synonyms. Niceness is simply the quality of being nice, especially in nice’s adjectival sense of “satisfactory, mildly approved,” as in It was her decency, her downright niceness that won them over. (But it could also reflect one or more of nice’s other senses.) Nicety, however, means “subtlety, detail, inner workings,” as in This book deals with the niceties of English usage.
