Late 18th century; earliest use found in Thomas Twining (bap. 1734, d. 1804), classical scholar and translator. From classical Latin miscellāneus + -ity, after miscellaneous.
Definition of miscellaneity in US English:
miscellaneity
noun
Miscellaneousness; an instance of this.
Origin
Late 18th century; earliest use found in Thomas Twining (bap. 1734, d. 1804), classical scholar and translator. From classical Latin miscellāneus + -ity, after miscellaneous.