Mnason in the Bible.

Who Mnason was.

Reminding, or remembrancer, a Christian of Jerusalem with whom Paul lodged (Acts 21:16). He was apparently a native of Cyprus, like Barnabas (11:19, 20), and was well known to the Christians of Caesarea (4:36). He was an “old disciple” (R.V., “early disciple”), i.e., he had become a Christian in the beginning of the formation of the Church in Jerusalem.

From Easton’s Bible Dictionary (1897).