Gadi
Gadi is named only as the father of Menahem, the Israelite who seized the throne of the northern kingdom by killing Shallum at Samaria. The name carries no narrative of its own; it survives in the regnal record as the patronymic that anchors his son's reign.
Father of Menahem
Menahem comes up out of Tirzah and strikes down the usurper Shallum at Samaria: "And Menahem the son of Gadi went up from Tirzah, and came to Samaria, and struck Shallum the son of Jabesh in Samaria, and slew him, and reigned in his stead" (2 Ki 15:14). The regnal formula that opens his reign repeats the patronymic: "In the nine and thirtieth year of Azariah king of Judah, Menahem the son of Gadi began to reign over Israel, [and reigned] ten years in Samaria" (2 Ki 15:17).