Smith's Bible Dictionary (1863)
(feminine of Ai), a place named by Isaiah, (Isaiah 10:28) in connection with Migron and Michmash probably the same as Ai.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
AI'ATH. Isa 10:28. Feminine form of Ai, and probably the same as Ai.
Hitchcock's Bible Names (1869)
same as Ai; an hour; eye; fountain