What name was Gideon given after he tore down his father's altar to Baal?

Answer: Jerubbaal

He was called Jerubbaal, "Let Baal contend with him," after his father Joash said Baal should defend himself if he was a god.

“So on that day Gideon was called Jerubbaal, that is to say, “Let Baal contend with him,” because he had torn down Baal’s altar.”— Judges 6:32 (BSB)