mod·​u·​lus | \ ˈmä-jə-ləs How to pronounce modulus (audio) \
plural moduli\ ˈmä-​jə-​ˌlī How to pronounce modulus (audio) , -​ˌlē \

Definition of modulus

1a : the factor by which a logarithm of a number to one base is multiplied to obtain the logarithm of the number to a new base
c(1) : the number (such as a positive integer) or other mathematical entity (such as a polynomial) in a congruence that divides the difference of the two congruent members without leaving a remainder — compare residue sense b
(2) : the number of different numbers used in a system of modular arithmetic
2 : a constant or coefficient that expresses usually numerically the degree to which a body or substance possesses a particular property (such as elasticity)

Examples of modulus in a Sentence

Recent Examples on the Web The modular operation is the act of taking the remainder when a number is divided by the modulus. Popular Mechanics, 21 Feb. 2021 In this scenario, responders’ only saving grace would be the use of a weak RSA modulus. Dan Goodin, Ars Technica, 7 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'modulus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of modulus

1753, in the meaning defined at sense 1a

History and Etymology for modulus

New Latin, from Latin, small measure

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Time Traveler for modulus

Time Traveler

The first known use of modulus was in 1753

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Dictionary Entries Near modulus



modulus of a logarithm

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Statistics for modulus

Cite this Entry

“Modulus.” Dictionary, Merriam-Webster, Accessed 17 Jan. 2022.

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More Definitions for modulus


mod·​u·​lus | \ ˈmäj-ə-ləs How to pronounce modulus (audio) \
plural moduli\ -​ˌlī How to pronounce modulus (audio) , -​ˌlē How to pronounce modulus (audio) \

Medical Definition of modulus

: a constant or coefficient that expresses usually numerically the degree to which a substance or body possesses a property (as elasticity)


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