DUODECIMO

a. n.

2 definitions — Webster’s Dictionary (1828)


1.
a.

Having twelve leaves to a sheet; as, a duodecimo from, book, leaf, size, etc.

2.
n.

A book consisting of sheets each of which is folded into twelve leaves; hence, indicating, more or less definitely, a size of a book; -- usually written 12mo or 12º.