heathen
n. countablen. someone who does not belong to a major religion or who does not follow the religious rules of their society. People sometimes use it as a joke to describe someone who is uneducated or lacks good manners.
n. an individual who does not acknowledge the God of the Bible, Torah, or Quran; historically applied to those practicing polytheism. In modern secular contexts, it often carries a humorous or derogatory connotation regarding a lack of cultural refinement.
He felt like a heathen because he didn't know the local customs.
The missionaries traveled to remote islands to spread their faith among the people they labeled as heathens.
From Middle English hethen, from Old English hǣþen, from Proto-West Germanic haiþin, from Proto-Germanic haiþīnaz (“heathen, pagan”, adjective), equivalent to heath (“heathland”) + -en. Cognate with West Frisian heiden, Dutch heiden, Middle High German heiden, German Heiden, German Heide, Swedish heden, Danish hedensk (from heden+sk), Icelandic heiðinn. See also Proto-Germanic *haiduz, Old Norse heiðr (honour, bright, moor), Icelandic heiður (honour).
Often used as a collective noun ('the heathen') in older literature to refer to a group of non-believers.