Synonyms of unfaithful

unfaithful 1 of 2

adjective

ˌən-ˈfāth-fəl 

as in traitorous

not true in one's allegiance to someone or something

colonists who later proved to be unfaithful to the cause of independence

Synonyms & Similar Words

• traitorous
• unreliable
• false
• faithless
• disloyal
• treacherous
• perfidious
• untrue
• inconstant
• fickle
• recreant
• untrustworthy
• irresponsible
• hesitant
• undependable
• uncertain
• faltering
• irresolute
• uninterested
• dubious
• apathetic
• trustless
• dispassionate
• vacillating
• wavering

Antonyms & Near Antonyms

• faithful
• loyal
• true
• constant
• responsible
• steady
• devout
• steadfast
• reliable
• devoted
• trustworthy
• fast
• dedicated
• dependable
• staunch
• dutiful
• solid
• down-the-line
• trusty
• tried
• unfaltering
• unhesitating
• determined
• resolute
• confirmed
• intent
• tried-and-true
• enthusiastic
• trustable
• inveterate
• passionate
• sworn
• unwavering
• ardent
• fervent
• impassioned
• avid
• fervid
• dyed-in-the-wool

unfaithfulness

2 of 2

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 unfaithful

Adjective

The singer gets back behind the wheel of the gold Trans Am an unfaithful friend stole from her all those years ago and revs up for a nuclear night out. — Larisha Paul, Rolling Stone, 26 Oct. 2026

In other words, some hallucinated or unfaithful answers originate before generation. — Patrick Dajos, Forbes.com, 23 Sep. 2026

Noun

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