The city of Philippi was a Roman colony (Acts 16:12), i.e., a military settlement of Roman soldiers and citizens, planted there to keep in subjection a newly-conquered district. A colony was Rome in miniature, under Roman municipal law, but governed by military officers (praetors and lictors), not by proconsuls. It had an independent internal government, the jus Italicum; i.e., the privileges of Italian citizens.

Noah Webster's New International Dictionary of the English Language

1. (n.) A company of people transplanted from their mother country to a remote province or country, and remaining subject to the jurisdiction of the parent state; as, the British colonies in America.

2. (n.) The district or country colonized; a settlement.

3. (n.) A company of persons from the same country sojourning in a foreign city or land; as, the American colony in Paris.

4. (n.) A number of animals or plants living or growing together, beyond their usual range.