Ad'adah (Heb. Adadah', עִרעָדָה, from the Syr., festival, or perhaps, by reduplication, boundary; Sept. Α᾿δαδά, v. r. Α᾿ρουήλ), a town in the southern part of the tribe of Judah, mentioned between Dimonah and Kedesh (Jos 15:22); probably situated in the portion afterward set off to Simeon (Jos 19:1-9). It is possibly the village Gadda mentioned by Eusebius and Jerome (Onomast. s.v. Γαδδά), lying on the eastern border of Daroma, opposite the Dead Sea. But see GADDAH. M. de Saulcy believes that he passed some ruins by this name on his way from the southern end of the Dead Sea to Hebron on the high ground after leaving Wady es-Zoweirah (Narrative, 1, 360, 430).