The word “gentile” ‘derives from Latin gentilis, which itself derives from the Latin gens … meaning clan or tribe” (Wikipedia). The word “goy” in Biblical Hebrew means “nation”. In fact, we are referred to as a goy kadosh. In Rabbinic Hebrew the word “goy” came to mean an idolater whereas a non-Jew who was not an idolater was called a ger toshav (without getting into the discussion regarding accepting them today). Ben Noach in the Gemara and Mishne Torah clearly is a general term for non-Jews. The Gemara (Megilla 13a) says that anyone who denies idolatry is called “Yehudi” (from meyahed – unite). In fact, the Gemara never refers to us a Yehudim (the use in Megillat Esther apparently refers to the fact that they were from Shevet Yehuda) but as Yisrael.
However, today the academic term “Noahide” has come to mean a non-Jew who has taken the sheva mitzvot upon himself. There are several Noahide organizations, each with its own website (you can google “Noahide” to find them).