Goy is either
1) Old Slavic interjection, similar to "Hey!". The most famous phrase with this interjection is "Go, my Russia, my dear!" From Sergey Yesenin's poem.
2) The designation of a non-Jew , which is used by Jews often in a degrading and discriminatory context. Translated from Hebrew, the word "goy" means simply "the people, the nation" and is occasionally used by Jews in relation to themselves, as, for example, in the expression "goy Kadosh" - holy people. The fact is that the Jews consider themselves to be the "chosen people", which was singled out by God among all nations for exemplary behavior. Therefore in Judaism there are quite chauvinistic traditions: believing Jews are forbidden to marry non-Jews, and also, for example, to drink wine, to which the non-Jew touched.