The AI-powered English dictionary
plural duodecimos
(paper, printing) A size of paper, so called because it is originally made by folding and cutting a single sheet from a printing press into 12 leaves; (5 by 7¾ inches): 6.5 to 7.5 inches high, approximately 4.5 inches wide. examples
A sheet or page of that size. examples
(printing) A book having pages of that size. quotations examples
In recent years, I have taken to reading while walking. I believe the Romantics were guilty of such behavior; a duodecimo was small enough to fit into a jacket pocket.
2015, William Logan, “A Critics Notebook,”, in Guilty Knowledge, Guilty Pleasure, page 304