eighteenmo

American

[ey-teen-moh] / ˈeɪˈtin moʊ /

noun

plural

eighteenmos

octodecimo.

eighteenmo British

/ ˈeɪˈtiːnməʊ /

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of eighteenmo

eighteen + -mo

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023