ف ن دf-n-d
(س) فَنِدَ يَفْنَدُ فَنَدًاfanida yafnadu fanadan: for the mind to weaken from old age, to talk nonsense, to dote. (This verb is not used in the Quran.)
Form II (tafʿīl) فَنَّدَ يُفَنِّدُ تَفْنِيْدًاfannada yufannidu tafnīdan: to declare someone senile and deluded. This root occurs only once in the Quran: ﴿اِنِّيْ لَاَجِدُ رِيْحَ يُوْسُفَ لَوْلَآ اَنْ تُفَنِّدُوْنِ﴾ (Yūsuf 12:94)