A book or pamphlet whose pages are of the size of the fourth of a sheet.
Having four leaves to the sheet.
In 1605 Don Quixote was published, in a quarto volume, by Juan de la Cuesta of Madrid. – The Story of Seville by Walter M. Gallichan
Its shape varied from time to time: now it was a folio: now a quarto. – Toronto of Old by Henry Scadding