unfaithful

[uhn-feyth-fuhl]

See more synonyms for unfaithful on Thesaurus.com

adjective

not faithful; false to duty, obligation, or promises; faithless; disloyal.
not sexually faithful to a spouse or lover.
not accurate or complete; inexact: an unfaithful translation.

Obsolete. unbelieving; infidel.

Origin of unfaithful

First recorded in 1350–1400, unfaithful is from the Middle English word unfeithful. See un-¹, faithful

Related formsun·faith·ful·ly, adverbun·faith·ful·ness, noun

Synonyms for unfaithful

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1. untrustworthy, deceitful, treacherous, recreant. 3. imprecise, untrue.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for unfaithfulness

defection, disloyalty, apostasy, perfidy, dereliction, treason, treachery, inconstancy, improbity, recreancy

Examples from the Web for unfaithfulness

Historical Examples of unfaithfulness

Philip was disgusted with her unfaithfulness to his friend, and that was the reason of his absence.
The Manxman
Hall Caine
It was not Audrey's unfaithfulness that had hurt him so much as her untruthfulness.
Audrey Craven
May Sinclair
The system works well, for unfaithfulness is said to be unknown.
Ireland as It Is
Robert John Buckley (AKA R.J.B.)
For three years my husband disgusted me with his unfaithfulness.
Possessed
Cleveland Moffett
Unfaithfulness and negligence are condemned and punished in both.
Jesus the Christ
James Edward Talmage

British Dictionary definitions for unfaithfulness

unfaithful

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 Formsunfaithfully, 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

Word Origin and History for unfaithfulness

unfaithful

adj.

mid-14c., "acting falsely," from un- (1) "not" + faithful. In Middle English it also had a sense of "infidel, unbelieving, irreligious" (late 14c.). Sense of "not faithful in marriage" is attested from 1828. Related: Unfaithfully; unfaithfulness.