According to The International Standard Bible Encyclopaedia, this word refers to “a (religious) story that has no connection with reality. ”
فَإِذَا ٱلْتَجَأْنَا إِلَى هذِهِ ٱلْآبَارِ ٱلْجَافَّةِ ،‏ نَعُودُ فَارِغِي ٱلْأَيْدِي وَخَائِبِينَ .‏