Easton's Bible Dictionary (1897)
(Heb. always with the article, “the” Millo). (1.) Probably the Canaanite name of some fortification, consisting of walls filled in with earth and stones, which protected Jerusalem on the north as its outermost defence. It is always rendered Akra i.e., “the citadel”, in the LXX. It was already existing when David conquered Jerusalem (2 Sam. 5:9). He extended it to the right and left, thus completing the defence of the city. It was rebuilt
by Solomon (1 Kings 9:15, 24; 11:27) and repaired by Hezekiah (2 Chr. 32:5). (2.) In Judg. 9:6, 20 it is the name of a rampart in Shechem, probably the “tower of Shechem” (9:46, 49).
Smith's Bible Dictionary (1863)
(a rampart, mound) a place in ancient Jerusalem. Both name and place seem to have been already in existence when the city was taken from the Jebusites by David. (2 Samuel 5:9; 1 Chronicles 11:8) Its repair or restoration was one of the great works for which Solomon raised his “levy,” (1 Kings 9:15,24; 11:27) and it formed a prominent part of the fortifications by which Hezekiah prepared for the approach of the Assyrians. (2 Chronicles 32:5)
The last passage seems to show that “the Milo” was part of the “city of David,” that is, of Zion. Comp. (2 Kings 12:20)
Hastings' Dictionary of the Bible (1898)
MIL'LO (a mound, rampart). "Millo" is used for a part of the citadel of Jerusalem, probably the rampart, or entrenchment. 2 Sam 5:9; 1 Kgs 9:15, 1 Kgs 9:24; 1 Kgs 11:27; 1 Chr 11:8. The same, or part of it, was probably the "house of Millo;" margin "Beth Millo." 2 Kgs 12:20; 2 Chr 32:5. Some think it means the "stronghold of Zion." Lewin suggests that it refers to the whole of the temple enclosure, while Conder curiously suggests that, from its
root, it may mean a pool. The first seems the more probable view. Millet (Sorghum Vulgare)
Hitchcock's Bible Names (1869)
fullness
Schaff's Bible Dictionary
MIL'LO, HOUSE OF. 1. The place where Joash was murdered in Jerusalem. 2 Kgs 12:20. See Millo, above.