unfaithful
un-FAYTH-ful
/ʌnˈfeɪθfl/
Not remaining loyal to one's spouse or sexual partner.
The most common and direct way to describe someone who cheats. It is less formal than 'infidelity' and less legal than 'adultery.'
The story behind the word. A simple combination of the Old English prefix 'un-' and the word 'faith' (from Old French 'feid'). It literally means 'without faith,' implying that a romantic relationship is built on a foundation of faith that has been removed.
Word relationships
- disloyal: A broader term that can apply to friends, countries, or partners.
- false: Poetic or archaic; 'a false lover' is one who is unfaithful.
- faithful: Remaining loyal and true to a partner.
- loyal: Giving or showing firm and constant support or allegiance.
Commonly confused with
- inaccurate: In some contexts, 'unfaithful' can mean 'not accurate' (like an unfaithful translation), but in romance, it only means cheating.
Word family
- unfaithfulness (noun): The state of being unfaithful.
Collocations
- unfaithful husband
- unfaithful wife
- be unfaithful to
Idioms & expressions
- cheat on
Example sentences
- "I have been unfaithful to you, and I cannot ask for your forgiveness." A confession in a story.
- "Being unfaithful often stems from a lack of communication within the marriage." A general statement about relationships.
Memory hook
UN- (not) + FAITHFUL. Simply not keeping the faith. Broken faith.
When not to use
It's quite versatile, but in very formal legal settings, 'adulterous' might be preferred.
Fun facts
- In the 16th century, 'unfaithful' was often used to describe someone who didn't believe in God (an infidel).
Related words
Explore more words
infidelity, disloyal, fidelity, perfidy, treachery, perfidious
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