What new name did Jeremiah give Pashhur after being released from the stocks?

Answer: Magor-missabib

The day after Pashhur released him from the stocks, Jeremiah said, "The LORD does not call you Pashhur, but Magor-missabib."

“The next day, when Pashhur released Jeremiah from the stocks, Jeremiah said to him, “The LORD does not call you Pashhur, but Magor-missabib.”— Jeremiah 20:3 (BSB)