Shabbos goy
non-Jewish person assisting in a task on Sabbath
A Shabbos goy is a Gentile who is asked by a Jew to do something on the Sabbath or one of the Jewish holidays that halakha says Jews can’t do on the Sabbath (or on the Jewish holidays).
Etymology
changeShabbos is a Yiddish way of pronouncing the Hebrew word Shabbat meaning the Sabbath. In the Torah, goy is Hebrew for nation so the Almighty says He will make the Israelites into a “goy gadol” (a great nation). But because of that, the Tanakh also says “Israel ve’ha’goyim” meaning Israel and the nations with the word goyim, which means nations, implying the other nations. Because of that the word Goyim eventually started being used to mean Gentiles with Goy meaning Gentile. So that Shabbos Goy literally means Sabbath Gentile.