Dictionary.com

unfaithful

[ uhn-feyth-fuhl ]
/ ʌnˈfeɪθ fəl /
Save This Word!

adjective
not faithful; false to duty, obligation, or promises; disloyal: Given how unfaithful the party has been to voters, it would be surprising if they won.
not sexually loyal to a spouse or lover; adulterous: She was concerned her husband would be unfaithful when he travelled.
not accurate or complete; inexact: The book was an unfaithful translation of the original.
Obsolete. without religious faith; unbelieving.
QUIZ
CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?

Origin of unfaithful

First recorded in 1350–1400; Middle English unfeithful, unfaithful; un-1 + faithful

OTHER WORDS FROM unfaithful

un·faith·ful·ly, adverbun·faith·ful·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use unfaithful in a sentence

British Dictionary definitions for unfaithful

unfaithful
/ (ʌnˈfeɪθfʊl) /

adjective
not true to a promise, vow, etc
not true to a wife, husband, lover, etc, esp in having sexual intercourse with someone else
inaccurate; inexact; unreliable; untrustworthyunfaithful copy
obsolete not having religious faith; infidel
obsolete not upright; dishonest

Derived forms of unfaithful

unfaithfully, adverbunfaithfulness, noun
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
FEEDBACK