Epikoros
Epikoros is a Jewish term figuratively meaning "a heretic", cited in the Mishnah, that refers to an individual who does not have a share in the World to Come:
The rabbinic literature uses the term epikoros without a specific reference to the Greek philosopher Epicurus, but some understand that the term is derived from his name. Epicurus was a materialist philosopher whose views contradicted Hebrew Bible, the strictly monotheistic conception of God in Judaism, and the Jewish belief in the World to Come.
The Talmudic interpretation is that the Aramaic word is derived from the Semitic root , and accordingly:
Marcus Jastrow, in his dictionary, identifies the term as, in fact, being an enlargement of פק"ר, which was then supported by its phonetic coincidence with the famed pagan philosopher.
According to Maimonides, scorning a Talmid Chakham is actually a singular case of disrespecting the entire Torah or its rabbinic scholar-sages. In his work Mishneh Torah, Maimonides rules that an epikoros is a person who denies that God communicates with humans through prophecy; one who denies the prophecy of Moses; or one who denies God's knowledge of the affairs of humans. Maimonides probably encountered the name of Epicurus sometime between composing his commentary on the Mishnah and the Guide for the Perplexed. In the first source, he states that the rabbinic term epikoros is an Aramaic word; in the Guide, Maimonides has become aware of the atheistic doctrine of the philosopher by that name. He cites the source of his information as Alexander of Aphrodisias's treatise On Providence.
Following the Christian censorship of the Talmud, starting with the aftermath of the Disputation of Barcelona and during the Roman and Spanish Inquisitions, the term spread within the Jewish classical texts. Censors shunned expressions like minim, which they viewed as referring to the Christian faith, and replaced them with the term epikoros or Epicurus. The censors also replaced terms that refer to Christians with the word, an abbreviation of, a belief that both Jews and their Christian censors abhorred.