Boyd’s Bible Dictionary:
(nations). In O. T. sense, all peoples not Jewish (Gen. 10:5; 14:1; Neh. 5:8). In N. T., Greeks and Romans seem to type Gentiles (Luke 2:32; Acts 26:17-20; Rom. 1:14-16; 9:24). “Isles of the Gentiles” (Gen. 10:5), supposed to embrace Asia Minor and Europe.
Concise Bible Dictionary:
A name commonly used in scripture to denote any and every nation except Israel. At times, when Israel as a people is referred to, the same words are used for them. Thus
1. goi, ἔθνος, is translated “nation,” and refers to the Jewish nation (Deut. 26:5; Luke 7:5; John 11:48). In the plural the same words refer to the nations generally in distinction from Israel, and are translated “nations,” “Gentiles,” and “heathen” (Deut. 18:9; Deut. 32:43; Isa. 60:3; Isa. 62:2; Joel 2:19; Acts 11:1,18; Acts 13:19; Acts 28:28; etc).
2. “Έλλην (in plural) is translated “Gentiles” (John 7:35; Rom. 2:9-10; Rom. 3:9; 1 Cor. 10:32; 1 Cor. 12:13), in contrast to the Jews; but would be better translated “Greeks,” as it is in most places.
God had raised a wall between the Jews and the Gentiles, which in Christ’s death was broken down for believers, “to make in himself of twain one new man” (Eph. 2:14). “There is neither Jew nor Greek.... for ye are all one in Christ Jesus” (Gal. 3:28). This does not touch unbelieving Jews and Gentiles, who are kept separate in God’s present and future dealings.
Jackson’s Dictionary of Scripture Proper Names:
nations