Brown Driver Briggs

 Attai = "opportune"
1. a Judaite, grandson of Sheshan the Jerahmeelite by daughter Ahlai
whom he gave in marriage to Jarha, his Egyptian slave; his grandson
Zabad was one of David's mighty warriors
2. one of the lion-faced warriors of Gad, captains of the host, who
joined David in the wilderness
3. the 2nd son of king Rehoboam of Judah by Maachah, the daughter of
Absalom