Easton’s Bible Dictionary

Greek : Found only in the New Testament, where a distinction is observed between "Greek" and "Grecian" (which see). The former is

  1. a Greek by race (Acts 16:1-3; 18:17; Romans 1:14), or
  2. a Gentile as opposed to a Jew (Romans 2:9,10). The latter, meaning properly "one who speaks Greek," is a foreign Jew opposed to a home Jew who dwelt in Palestine.

The word "Grecians" in Acts 11:20 should be "Greeks," denoting the heathen Greeks of that city, as rendered in the Revised Version according to the reading of the best manuscripts ("Hellenes").