{interj.} May God prevent (something from happening); I hope that will not happen or is not true. * /Someone told the worried mother that her son might have drowned. She said, "God forbid!"/ * /God forbid that the dam break and flood the valley!/ Compare: PERISH THE THOUGHT.
GOD FORBID
Meaning of GOD FORBID in English
Slang English vocab. Английский сленговый словарь. 2012