Unfaithful

/ʌnˈfeɪθfəl/

Meaning & Definition

adjective
not loyal or faithful; disloyal.
She felt heartbroken when she discovered that her partner had been unfaithful.
having sexual relations with someone other than one's spouse or partner.
His unfaithful behavior led to the breakdown of their marriage.
not adhering to or failing to fulfill obligations or duties.
The unfaithful servant was dismissed for stealing from his employer.

Etymology

From un- (not) + faithful (loyal, devoted)

Common Phrases and Expressions

unfaithful partner
a partner who is not loyal in a romantic relationship
being unfaithful
the act of being disloyal in a commitment
unfaithful spouse
a married person who engages in romantic relations outside their marriage

Related Words

faithful
loyal, devoted to someone or something
fidelity
faithfulness to a person, cause, or belief demonstrated by continuing loyalty

Slang Meanings

two-timer
He's a real two-timer, always cheating on his girlfriend.
cheater
She found out he's just a cheater, breaking her heart.