An island of the Aeagean sea, to which the apostle and evangelist John was banished by Domitian, A. D. 95, Revelation 1:9. It is a rocky and desolate island, about twenty-eight miles in circumference, with a bold and deeply indented shore; and was used by the Romans as a place of banishment for many criminals. It lies between Samos and Naxos, about forty miles west by south from the promontory of Miletus; and contains at present some four thousand inhabitants, mostly Greeks. Its principal port is a deep bay on the northeast side; the town lying on a high and steep hill, the summit of which is crowned by the old and castle-like monastery of St. John. Half way down the hill is a natural grotto, now covered by a Greek chapel, school, etc. In this cave, over-looking the sea and its islands towards his beloved Ephesus, tradition says that John saw and recorded his prophetic visions. The island is now called Patino; and the port Patmo, or San Giovanni di Patino.
Source: ATS Bible Dictionary
Patmos
A small rocky and barren island, one of the group called the "Sporades," in the AEgean Sea. It is mentioned in Scripture only in Revelation 1:9. It was on this island, to which John was banished by the emperor Domitian (A.D. 95), that he received from God the wondrous revelation recorded in his book. This has naturally invested it with the deepest interest for all time. It is now called Patmo. (See JOHN .)
Source: Easton's Bible Dictionary
Patmos
(Revelation 1:9) a rugged and bare island in the AEgean Sea, 20 miles south of Samos and 24 west of Asia Minor. It was the scene of the banishment of St. John in the reign of Domitian, A.D. 95. Patmos is divided into two nearly equal parts, a northern and a southern, by a very narrow isthmus where, on the east side are the harbor and the town. On the hill to the south, crowning a commanding height, is the celebrated monastery which bears the name of "John the Divine." Halfway up the descent is the cave or grotto where tradition says that St. John received the Revelation.