eighteenmo

[ey-teen-moh]

noun

plural

eighteenmos 

1. octodecimo.

eighteenmo

/ ˈeɪˈtiːnməʊ /

noun

1. Also called: octodecimo. Often written: 18mo.  18°. a book size resulting from folding a sheet of paper into 18 leaves or 36 pages

2. a book of this size

Word History and Origins

Origin of eighteenmo¹

eighteen + -mo

Example Sentences

Other sizes occasionally used are called “sixteenmo” or “sextodecimo,” “eighteenmo” or “octodecimo,” etc.

From Project Gutenberg