Synonyms of unfaithfulness

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

• infidelity
• adultery
• betrayal
• faithlessness
• disloyalty
• perfidy
• inconstancy
• treachery
• perfidiousness
• falseness
• falsity
• deception
• treason
• duplicity
• lying
• deceit
• double-dealing
• sellout
• double cross

Antonyms & Near Antonyms

• faithfulness
• loyalty
• faith
• fidelity
• devotion
• allegiance
• constancy
• fealty
• steadfastness
• reliability
• devotedness
• dependability
• honesty
• staunchness
• trustworthiness

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
• treason
• infidelity
• faithlessness
• disloyalty
• deception
• perfidy
• abandonment
• falseness
• backstabbing
• deceit
• lying
• sellout
• double cross
• falsity
• desertion
• two-timing
• business
• duplicity
• double-dealing
• fraud
• informing
• guile
• trickery
• two-facedness
• snitching
• talebearing

Antonyms & Near Antonyms

• faithfulness
• loyalty
• fidelity
• allegiance
• devotion
• steadfastness
• fealty
• reliability
• trustworthiness
• dependability
• defense
• staunchness
• 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
• misconduct
• cheating
• infidelity
• treachery
• affair
• two-timing
• faithlessness
• promiscuity
• disloyalty
• romance
• perfidy
• inconstancy
• love
• infatuation
• criminal conversation
• perfidiousness
• falseness
• intrigue
• free love
• amour
• love affair
• flirtation
• entanglement
• fling
• attachment
• liaison
• passion

Antonyms & Near Antonyms

• fidelity
• faithfulness
• loyalty
• devotion
• allegiance
• dedication
• constancy
• steadfastness
• fealty
• devotedness

Example Sentences

Recent Examples of unfaithfulness

Bharathram thought maybe the assumption of unfaithfulness was wrong, so the group adapted Moody’s method to instead try to prove faithfulness. — Lyndie Chiou, Scientific American, 24 July 2026

Coming to the glum realization that love isn’t outlasting infatuation is trickier to write about than a more incendiary subject like unfaithfulness, but Rodrigo pulls it off. — Chris Willman, Variety, 12 June 2026

According to The Daily Mail, unfaithfulness might have been the cause. — Lizzie Lanuza, StyleCaster, 12 Jan. 2026

Harbour also recently made headlines following the release of estranged wife Lily Allen's latest album, West End Girl, which contained references many interpreted as pointing toward alleged unfaithfulness on Harbour's part, though the actor isn't explicitly named in the lyrics. — Joey Nolfi, Entertainment Weekly, 7 Nov. 2025

Milvia Marigliano is a hoot as Coco Vulori, an old dear friend with some very loud opinions to express, and maybe the key to helping DeSantis solve his wife’s onetime unfaithfulness. — Pete Hammond, Deadline, 27 Aug. 2025