unfaithful
adjective
un·faith·ful ˌən-ˈfāth-fəl 
: 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
unfaithfully
ˌən-ˈfāth-fə-lē
adverb unfaithfulness noun
Synonyms
- disloyal
- faithless
- false
- fickle
- inconstant
- perfidious
- recreant
- traitorous
- treacherous
- untrue
See all Synonyms & Antonyms 
Example Sentences
colonists who later proved to be unfaithful to the cause of independence
Recent Examples on the Web The analysis showed the most unfaithful city in the U.S. was Dallas, Texas. 
Leada Gore | Lgore@al.com, al, 24 Aug. 2022 The comedy, which is currently airing on Apple TV+, stars Rudolph as Molly Wells, a woman who comes into an $87 billion settlement after divorcing her unfaithful tech entrepreneur husband (Severance's Adam Scott). Leena Kim, Town & Country, 5 Aug. 2022 The mod in question, dubbed BetterOrigins, was poised to correct apparently unfaithful elements found in the Sonic Origins versions of classic Sonic the Hedgehog games. Sam Machkovech, Ars Technica, 12 July 2022 This includes Amazon’s adaptation of The Wheel Of Time—a bizarrely unfaithful, cheap-feeling rendition of Robert Jordan’s epic fantasy. Erik Kain, Forbes, 29 June 2022 The protagonist, Kafuku, is a middle-aged actor mourning the death of his unfaithful wife. Los Angeles Times, 6 June 2022 And is dementia, as a form of amnesia, actually merciful, at least for someone with Ptolemy’s memories—of lynchings, fires, an unfaithful wife ( Cynthia Kaye McWilliams ), friends long gone and justice denied? John Anderson, WSJ, 10 Mar. 2022 In early July, the lives of the TikTok star, actress, and singer’s family were shaken up when allegations surfaced that her father, Monty Lopez, had apparently been unfaithful to Rae’s mother, Sheri Nicole Easterling. Brittany Spanos, Rolling Stone, 19 Aug. 2022 Baby True was born in Cleveland, Ohio, on April 12, 2018, just days after news broke that Thompson had allegedly been unfaithful to Kardashian. Sophie Dodd, PEOPLE.com, 20 July 2022 See More
Leada Gore | Lgore@al.com, al, 24 Aug. 2022 The comedy, which is currently airing on Apple TV+, stars Rudolph as Molly Wells, a woman who comes into an $87 billion settlement after divorcing her unfaithful tech entrepreneur husband (Severance's Adam Scott). Leena Kim, Town & Country, 5 Aug. 2022 The mod in question, dubbed BetterOrigins, was poised to correct apparently unfaithful elements found in the Sonic Origins versions of classic Sonic the Hedgehog games. Sam Machkovech, Ars Technica, 12 July 2022 This includes Amazon’s adaptation of The Wheel Of Time—a bizarrely unfaithful, cheap-feeling rendition of Robert Jordan’s epic fantasy. Erik Kain, Forbes, 29 June 2022 The protagonist, Kafuku, is a middle-aged actor mourning the death of his unfaithful wife. Los Angeles Times, 6 June 2022 And is dementia, as a form of amnesia, actually merciful, at least for someone with Ptolemy’s memories—of lynchings, fires, an unfaithful wife ( Cynthia Kaye McWilliams ), friends long gone and justice denied? John Anderson, WSJ, 10 Mar. 2022 In early July, the lives of the TikTok star, actress, and singer’s family were shaken up when allegations surfaced that her father, Monty Lopez, had apparently been unfaithful to Rae’s mother, Sheri Nicole Easterling. Brittany Spanos, Rolling Stone, 19 Aug. 2022 Baby True was born in Cleveland, Ohio, on April 12, 2018, just days after news broke that Thompson had allegedly been unfaithful to Kardashian. Sophie Dodd, PEOPLE.com, 20 July 2022 See More Word History
First Known Use
15th century, in the meaning defined above
Kids Definition
unfaithful
adjective
un·faith·ful ˌən-ˈfāth-fəl
: not faithful : disloyal
unfaithfulness
noun
1
as in infidelity
lack of faithfulness especially to one's husband or wife he eventually forgave his wife's unfaithfulness Synonyms & Similar Words
Relevance
- infidelity
- adultery
- betrayal
- faithlessness
- disloyalty
- perfidy
- perfidiousness
- inconstancy
- treachery
- falseness
- duplicity
- deception
- falsity
- treason
- deceit
- lying
- sellout
- double cross
- double-dealing
Antonyms & Near Antonyms
- faithfulness
- fidelity
- loyalty
- devotion
- faith
- allegiance
- constancy
- fealty
- steadfastness
- devotedness
- reliability
- dependability
- trustworthiness
- honesty
- staunchness
2
as in betrayal
the act or fact of violating the trust or confidence of another the jaw-dropping unfaithfulness of the person she had considered her best friend was deeply hurtful Synonyms & Similar Words
- betrayal
- treachery
- infidelity
- treason
- faithlessness
- disloyalty
- perfidy
- deception
- abandonment
- backstabbing
- falseness
- deceit
- lying
- desertion
- sellout
- falsity
- double cross
- two-timing
- duplicity
- business
- fraud
- guile
- two-facedness
- informing
- double-dealing
- trickery
- snitching
- talebearing
Antonyms & Near Antonyms
- faithfulness
- fidelity
- loyalty
- allegiance
- devotion
- steadfastness
- fealty
- reliability
- trustworthiness
- dependability
- staunchness
- defense
- protection
- shield
- safeguard
3
as in adultery
a sexual encounter or relationship between a married person and someone other than their spouse there were charges of unfaithfulness on both sides Synonyms & Similar Words
- adultery
- cheating
- misconduct
- infidelity
- treachery
- faithlessness
- disloyalty
- two-timing
- promiscuity
- affair
- perfidy
- inconstancy
- affaire
- romance
- perfidiousness
- infatuation
- love
- falseness
- amour
- criminal conversation
- intrigue
- flirtation
- free love
- entanglement
- love affair
- fling
- attachment
- liaison
- passion
Antonyms & Near Antonyms
- faithfulness
- fidelity
- loyalty
- devotion
- allegiance
- dedication
- constancy
- steadfastness
- devotedness
- fealty
- ease off
- ease someone's (troubled) mind
- ease someone's mind
- ease someone's troubled mind
- ease up
- ease up on
- eased
- eased (up)
- eased up
- eased up on
- eased-up
- easeful
- easefully
- easefulnesses
- easel
- easel painting
- easel picture
- easel-backed
- easelback
- easeled
- easeless
- easels
- easement
- easement curve
- easements