From BiblePortal Wikipedia

Hastings' Dictionary of the New Testament [1]

Elamites are mentioned in  Acts 2:9 among the sojourners in Jerusalem on the Day of Pentecost. Jews settled in Elam during the post-exilic period, whence they and their descendants came up to the Holy City for the annual religions festivals. Elam lay due east of Babylonia and the lower Tigris, and corresponds to the modern Khuzistan . Its ruling cities were Shushan (or Susa) and Ansan (or Anzan), and the earliest native rulers called themselves patesis , or ‘viceroys,’ in acknowledgment of dependence upon Babylonia. The native Elamites had been gradually encroached upon, from the west, by invading Semites, who brought their own system of writing with them. This system was adopted by the Elamite princes for many of their votive tablets and inscribed monuments. For a brief period after 2300 b.c. Elamite chieftains ruled in Babylonia, but their power was broken by Hammurabi, whose son Samsu-iluna finally restored Babylonian supremacy.

Literature.-L. W. King and H. R. Hall, Egypt and Western Asia in the Light of Recent Discoveries , 1907, ch. v.; H. Winckler, History of Babylonia and Assyria , Eng. translation, 1907, ch. ii.; articles ‘Elam’ in Realencyklopädie für protestantische Theologie und Kirche 3 and Jewish Encyclopedia , and ‘Elam, Elamites’ in Hasting's Dictionary of the Bible (5 vols) .

A. W. Cooke.

Morrish Bible Dictionary [2]

Inhabitants of Elam, some of whom were located in Palestine.  Ezra 4:9 . Some of the same name, 550 years after, were present at Jerusalem on the day of Pentecost, but these were doubtless Jews from Elam.  Acts 2:9 .