"A country to the north-west of Macedonia, on the eastern shores" "of the Adriatic, now almost wholly comprehended in Dalmatia, a" name formerly given to the southern part of Illyricum (2 Tim. 4:10). It was traversed by Paul in his third missionary journey (Rom. 15:19). It was the farthest district he had reached in preaching the gospel of Christ. This reference to Illyricum is "in harmony with Acts 20:2, inasmuch as the apostle's journey" over the parts of Macedonia would bring him to the borders of Illyricum.

See where Illyricum occurs in the Bible...

Definition of Illyricum:
"joy; rejoicing"