[ doo-uh-des-uh-moh, dyoo- ]
/ ˌdu əˈdɛs əˌmoʊ, ˌdyu- /
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noun, plural du·o·dec·i·mos.
Also called twelvemo. a book size of about 5 × 7½ inches (13 × 19 centimeters), determined by printing on sheets folded to form 12 leaves or 24 pages. Symbol: 12 mo, 12°
a book of this size.
in duodecimo; twelvemo.
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Origin of duodecimo

First recorded in 1650–60; short for Latin in duodecimō “in twelfth”
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use duodecimo in a sentence

British Dictionary definitions for duodecimo

/ (ˌdjuːəʊˈdɛsɪˌməʊ) /

noun plural -mos
Also called: twelvemo a book size resulting from folding a sheet of paper into twelve leavesOften written: 12mo, 12°
a book of this size

Word Origin for duodecimo

C17: from Latin phrase in duodecimō in twelfth, from duodecim twelve
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