Goy or Goyim is a term for a gentile or a non-Jew.
The word of Hebrew origin was adopted into English from Yiddish.
The meaning of the word goy in Hebrew evolved to mean "non-Jew" in the Hellenistic (300-30 BC) and Roman periods, as both Rabbinical texts and then Christian theology placed increasing emphasis on a binary division between Jews and non-Jews.
As a word principally used by Jews to describe non-Jews, it is a term for the ethnic out-group. In modern usage in English, the extent to which goy is derogatory is a point of discussion in the Jewish community.