un·​faith·​ful | \ ˌən-ˈfāth-fəl How to pronounce unfaithful (audio) \

Definition of unfaithful

: not faithful:
a : not adhering to vows, allegiance, or duty : disloyal an unfaithful friend
b : not faithful to marriage vows suspected her husband of being unfaithful
c : inaccurate, untrustworthy an unfaithful copy of a document

Keep scrolling for more

Other Words from unfaithful

unfaithfully \ ˌən-​ˈfāth-​fə-​lē How to pronounce unfaithfully (audio) \ adverb
unfaithfulness noun

Examples of unfaithful in a Sentence

colonists who later proved to be unfaithful to the cause of independence

Recent Examples on the Web

Fosse was unfaithful to McCracken with Verdon for several years before the divorce (Wasson tracks the affair back to Damn Yankees), as McCracken’s health was declining due to complications from diabetes. Emma Dibdin, Harper's BAZAAR, "A Complete Timeline of the Real Relationship Between Bob Fosse and Gwen Verdon," 9 Apr. 2019 Though clad in the fashions of the time, the unfaithful wife is Aphrodite, the goddess of love; her handsome paramour is Ares, the god of war; and the outraged husband who has snared the cheating pair in a powerful golden mesh is... Meghan Cox Gurdon, WSJ, "Children’s Books: Love and War as the Meddling Gods Look On," 1 Mar. 2019 This may be, understandably, pretty off-putting, considering the fact that the woman, unfaithful or not, seems to have little say in that matter. Jennifer Wright, Harper's BAZAAR, "The Catholic Church Has No Moral Argument on Abortions," 11 Feb. 2019 Just a few weeks ago the 34-year-old reality star confirmed on Instagram that Tristan had indeed been unfaithful but, in the five months since the incident was caught on camera, the couple have seemingly gone from strength to strength. Lucy Wood, Marie Claire, "Khloe Kardashian Is Moving Back to Cleveland for Family Life with Tristan and True Thompson," 20 Sep. 2018 And if her husband Jay Z’s recently released confessional album 4:44 is any indicator, perhaps feminism helped Bey find her power when she was confronted with an unfaithful partner. Brittney Cooper, Cosmopolitan, "Why Feminism Needed Beyonce," 14 Feb. 2018 There is perhaps no more virulent form of public scorn than the kind heaped upon the openly unfaithful. Marcia Desanctis, Town & Country, "Mark Sanford, Act II," 14 Feb. 2013 Jose Canseco claims that 43-year-old Rodriguez has allegedly been unfaithful to J.Lo with Canseco’s ex-wife. Lucy Wood, Marie Claire, "Who is Jose Canseco, Alex Rodriguez's Yankees Colleague Speaking Out on His Relationship?," 11 Mar. 2019 Last year, reports broke that the NBA player was unfaithful to the reality star days before the birth of their daughter, True. Erica Gonzales, Harper's BAZAAR, "How Kylie Jenner and the Kardashians Reacted to Tristan Thompson and Jordyn Woods' Cheating Allegations," 20 Feb. 2019

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

See More

First Known Use of unfaithful

15th century, in the meaning defined above

Keep scrolling for more

Learn More about unfaithful

Statistics for unfaithful

Last Updated

14 May 2019

Look-up Popularity

Time Traveler for unfaithful

The first known use of unfaithful was in the 15th century

See more words from the same century

Keep scrolling for more

More Definitions for unfaithful



English Language Learners Definition of unfaithful

: having a sexual relationship with someone who is not your wife, husband, or partner
: not accurate


un·​faith·​ful | \ ˌən-ˈfāth-fəl How to pronounce unfaithful (audio) \

Kids Definition of unfaithful

: not faithful : disloyal

Keep scrolling for more

Comments on unfaithful

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


to make a payment or contribution

Get Word of the Day daily email!

Test Your Vocabulary

Time Traveler Quiz: Which Word Came First?

  • time traveler quiz which word came first
  • Which came first?
Name That Thing

Test your visual vocabulary with our 10-question challenge!


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!