[doo-uh-des-uh-muh l, dyoo-]


pertaining to twelfths or to the number 12.
proceeding by twelves.


one of a system of numbers based on the number 12.
one of 12 equal parts.

Origin of duodecimal

1705–15; < Latin duodecim twelve + -al1
Related formsdu·o·dec·i·mal·i·ty, noundu·o·dec·i·mal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for duodecimal

duodecimal, twelfth, duodenary

Examples from the Web for duodecimal

Historical Examples of duodecimal

  • They learned to use both the decimal and the duodecimal systems (nowadays we use only the decimal system, which is a great pity).

    Ancient Man

    Hendrik Willem van Loon

  • And at the very first in Egypt, Chalda, and among the Turanian races generally, we find this duodecimal system firmly established.

    Human Origins

    Samuel Laing

  • The fact is noted by Mr. Jayaram Moodaliar that the Kondh system of notation is duodecimal.

  • But what a pity that we have not 12 fingers, with duodecimal fractions instead of decimals!

  • If possible, this is even more true here than in the case of the duodecimal system.

British Dictionary definitions for duodecimal



relating to twelve or twelfths


a twelfth
one of the numbers used in a duodecimal number system
Derived Formsduodecimally, adverb
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

Word Origin and History for duodecimal

1714, from Latin in duodecimo (see duodecimo).

Online Etymology Dictionary, © 2010 Douglas Harper

duodecimal in Science



Relating to or based on the number 12; having 12 as the base. In the duodecimal number system, each digit represents a multiple of a power of 12 instead of 10. Thus the duodecimal number 24 represents (2 X 121) + (4 X 120), or 28.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.