Easton's Bible Dictionary (1897)
Place of abundance, a place on the east of Jordan and west of the Euphrates where David gained a great victory over the Syrian army (2 Sam. 10:16), which was under the command of Shobach. Some would identify it with Alamatta, near Nicephorium.
Smith's Bible Dictionary (1863)
(stronghold), a place east of the Jordan but west of the Euphrates at which the Syrians were collected by Hadarezer, and where David met and defeated them. (2 Samuel 10:16,17)
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
HE'LAM (stronghold), usually regarded as the place where David gained a victory over the Syrians, 2 Sam 10:16-17, and by some identified with Almanethn, west of the Euphrates; but this is merely conjecture. The Latin Version does not regard the word as a proper name, but renders it "army" or "host."
Hitchcock's Bible Names (1869)
their army; their trouble