A sheet of paper folded into eight leaves. Commonly speaking, it is restricted to the size obtained by folding sheets of a certain determinate magnitude, so that the leaves shall be not less than five and a half inches nor more than eight inches in width, and not of less length than eight inches nor more than twelve. The ordinary octavo of this country is 6 by 9.5 inches…

[cite: American Dictionary of Printing and Bookmaking (1894)]

Last edited by DBurnette.