The word אמלל appears 18 times in TaNa”KH.  I Samuel (once), Isaiah (six times), once each in Jeremiah, Ezekiel, Hosea, Yoel (twice), Nahum (twice), and once each in Psalms, Lamentations, and Nehemiah.

HALOT gives the root as אמל, from the Akkadian ummulu (to be sad) which they translate variously as “to dry out”, “to dwindle”, “hot with fever”, and “frail” or “wretched”