noun / adjective
infidel
IN-fih-dul/ˈɪnfɪdəl/
A person who rejects or lacks a particular religious faith, or describing such a person, usually disparagingly.
The nonparticipant stands apart from the ritual, regarded by some believers as an infidel.

Etymology
The pieces mean “not faithful,” which developed into “unbelieving” in religious use. As a noun, the word labels someone outside the religion treated as the speaker’s standard.
In context
street brawls and even pitched battles between knights who wore different crosses but worshiped the same god. Could you imagine it? Two orders of holy warriors sworn to fight the infidel
More examples
- He resents being called an infidel for practicing a different religion.
- The old sermon condemns the customs of "infidel nations."
- She rejects the label "infidel" and describes herself as an atheist.
Forms
infidel · infidels
Similar words
- unbeliever
- Lacks religious belief; does not necessarily imply hostile judgment.
- atheist
- Lacks belief in gods, rather than one particular religion.