The definition of infidelity is the act of behaving unfaithfully and cheating on a spouse or significant other.
An example of infidelity is when you have an affair when you are married and cheat on your spouse.
- the fact or state of being an infidel
- unfaithfulness or disloyalty to another; esp., sexual unfaithfulness of a husband or wife; adultery
- pl. -·ties an unfaithful or disloyal act
Origin of infidelityClassical Latin infidelitas from infidelis: see infidel
- a. Unfaithfulness to a sexual partner, especially a spouse.b. An act of sexual unfaithfulness.
- Lack of fidelity or loyalty.
- Lack of religious belief.
- (religious): infidel
From Middle French infidélité, from Latin infidelitas