Boyd’s Bible Dictionary:

(trouble). Originally a narrow strip of country on north coast of Peloponnesus, but Achaia and Macedonia came to designate all Greece (Acts 18:12,27; 19:2112And when Gallio was the deputy of Achaia, the Jews made insurrection with one accord against Paul, and brought him to the judgment seat, (Acts 18:12)
27And when he was disposed to pass into Achaia, the brethren wrote, exhorting the disciples to receive him: who, when he was come, helped them much which had believed through grace: (Acts 18:27)
21After these things were ended, Paul purposed in the spirit, when he had passed through Macedonia and Achaia, to go to Jerusalem, saying, After I have been there, I must also see Rome. (Acts 19:21)
; Rom. 15:2626For it hath pleased them of Macedonia and Achaia to make a certain contribution for the poor saints which are at Jerusalem. (Romans 15:26); 2 Cor. 1:1; 9:2; 11:101Paul, an apostle of Jesus Christ by the will of God, and Timothy our brother, unto the church of God which is at Corinth, with all the saints which are in all Achaia: (2 Corinthians 1:1)
2For I know the forwardness of your mind, for which I boast of you to them of Macedonia, that Achaia was ready a year ago; and your zeal hath provoked very many. (2 Corinthians 9:2)
10As the truth of Christ is in me, no man shall stop me of this boasting in the regions of Achaia. (2 Corinthians 11:10)
; 1 Thess. 1:7-87So that ye were ensamples to all that believe in Macedonia and Achaia. 8For from you sounded out the word of the Lord not only in Macedonia and Achaia, but also in every place your faith to God-ward is spread abroad; so that we need not to speak any thing. (1 Thessalonians 1:7‑8)).

Concise Bible Dictionary:

Strong’s Dictionary of Greek Words:

of uncertain derivation; Achaia (i.e. Greece), a country of Europe
KJV Usage:

Jackson’s Dictionary of Scripture Proper Names:


Potts’ Bible Proper Names:

A brother; grief or trouble:―a country of Europe, Acts 18:12. {Frater}