Boyd’s Bible Dictionary:
(market place of Appius). A town, 43 miles S. E. of Rome, on the Appian Way (Acts 28:15).
Concise Bible Dictionary:
Station on the Appian Way, the main road from Rome to the Bay of Naples, where brethren went to meet Paul though 43 miles from Rome (Acts 28:15). The road was 18 to 22 feet wide, and parts of the ancient paving stones may still be seen. It was constructed by Appius Claudius, hence its name.
Jackson’s Dictionary of Scripture Proper Names:
persuasive mart