Probably from the passive participle of the same as Adlay; Adullam, a place in Palestine -- Adullam.
see HEBREW Adlay
H5725. Adullam
עֲדֻלָּם proper name, of a location old Canaanite city, ᵐ5 Οδολλαμ, with king Joshua 12:15 (D), in the שְׁפֵלָה 15:35 (P; ᵐ5L Αδαλαμ ), compare Micah 1:15; Nehemiah 11:30; (re-)built by Rehod. according to 2 Chronicles 11:17 (Οδολαμ); ׳ע מְעָרַת (read מְצָדַת מְצֻדַת,, see מְעָרָה below I. ערר) 1 Samuel 22:1; 2 Samuel 23:13; 1 Chronicles 11:15; site probably I`d-el-Mîye (`Aid el-Ma), approximately 13 miles west-southwest from Bethlehem, see GASmGeogr.229 BuhlGeogr.193 and references.