COMMONPLACE, a passage or argument appropriate to several cases ; a "common-place book" is a collection of such passages or quotations arranged for reference under general heads. To such a book the name adversaria was given, which is an adap tation of the Latin adversaria scripta, notes written on one side, the side opposite (adversus) of a paper or book. From its original meaning the word came to be used for a platitude or truism, being equivalent to trivial or ordinary. It was first spelled as two words, then with a hyphen, and so is still—in the sense of a "common place book."