infidel
Heretic to crusaders
Infidel is someone who doesn't share a particular religious faith—historically used by Christians for non-Christians and by Muslims for non-Muslims.
The word carries hostility: it frames the outsider as not merely different but faithless or treacherous.
In secular contexts, infidel sometimes appears ironically or defiantly: I'm a proud infidel when it comes to their dietary rules.
One who renounces faith
- hereticChallenger of official doctrine
- blasphemerOne who insults deity
- heathenIrreligious nonbeliever
- paganNon-mainstream religion follower
unbeliever · nonbeliever · disbeliever · godless · irreligious · kafir · schismatic · excommunicated
One denying gods exist
- agnosticFlexible across platforms
- skepticOne who doubts claims
- secularistAdvocate for nonreligious governance
- freethinkerRejects doctrine for reason
humanist · rationalist · nontheist · materialist · doubter · questioner · irreligion · disbelief
Non-native person
- strangerPerson not yet known
- alienNon-native being
- otherDistinct from those mentioned
- enemyHostile opposing party
adversary · foe · outcast · pariah · interloper · outgroup · them · crusades
One who betrays allegiance
- turncoatOne who betrays allegiance
- renegadeDeserter of a cause
- defectorOne who abandons allegiance
- deserterOne who abandons duty
recreant · perfidious · treacherous · disloyal · double-crosser · backstabber · treason · treachery
apostate
One who renounces faith
- hereticChallenger of official doctrine
- blasphemerOne who insults deity
- heathenIrreligious nonbeliever
pagan · unbeliever · nonbeliever · disbeliever · godless · irreligious · kafir · schismatic · excommunicated · anathema
atheist
One denying gods exist
- agnosticFlexible across platforms
- skepticOne who doubts claims
- secularistAdvocate for nonreligious governance
freethinker · humanist · rationalist · nontheist · materialist · doubter · questioner · irreligion · disbelief · godlessness
foreigner
Non-native person
enemy · adversary · foe · outcast · pariah · interloper · outgroup · them · crusades · jihad
traitor
One who betrays allegiance
deserter · recreant · perfidious · treacherous · disloyal · double-crosser · backstabber · treason · treachery · disloyalty
adulterer
Unfaithful married person
- cheaterOne who acts dishonestly
- philandererHabitual romantic cheater
- cheatAct dishonestly to win
affair · adultery · unfaithful · two-timer · cuckold · betrayed · straying · wandering · lothario · jezebel
- CrusadesFirst Crusade, crusade, crusader, Third Crusade, Knights Templar
- nonbelieversatheist, atheists, agnostic, agnostics, nonbeliever
- sectarianismsectarianism, sectarian, sect, schism, schismatic
- sinnerssinner, transgressor, evildoer, wrongdoer, blasphemer
- freethinkersfreethinker, freethinkers, secularists, rationalist, rationalists
- FaithsChristians, Catholics, Buddhists, Hindus, Jews
- marital infidelityCheating within wedlock