mod·u·lus | \ˈmä-jə-ləs \
plural moduli\-ˌlī, -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

b : absolute value sense 2

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

In this scenario, responders’ only saving grace would be the use of a weak RSA modulus. Dan Goodin, Ars Technica, "Stymied by browsers, attackers embed Flash 0-day inside MS Office document," 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

Keep scrolling for more

Learn More about modulus

Statistics for modulus

Look-up Popularity

Time Traveler for modulus

The first known use of modulus was in 1753

See more words from the same year

Keep scrolling for more

More Definitions for modulus


mod·u·lus | \ˈmäj-ə-ləs \
plural moduli\-ˌlī, -ˌlē \

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)

Comments on modulus

What made you want to look up modulus? Please tell us where you read or heard it (including the quote, if possible).


a state of commotion or excitement

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!