Bible Dictionaries
Quarto

Webster's Dictionary

(1):

(n.) Originally, a book of the size of the fourth of sheet of printing paper; a size leaves; in present usage, a book of a square or nearly square form, and usually of large size.

(2):

(a.) Having four leaves to the sheet; of the form or size of a quarto.

Bibliography Information
Webster, Noah. Entry for 'Quarto'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​q/quarto.html. 1828.