ف ء دf-ʾ-d
(ف) فَأَدَ يَفْأَدُ فَأْدًاfaʾada yafʾadu faʾdan: (1) to strike someone on the heart (2) to be struck in the heart; to be cowardly. (This verb is not used in the Quran.)
فُؤَادٌfuʾād pl. اَفْئِدَةٌafʾidah (noun (ism dhāt)): the heart; the lexicographers say that this word is used for the heart with regard to its heat and emotions. ﴿مَا كَذَبَ الْفُؤَادُ مَا رَاٰى﴾ (An-Najm 53:11); ﴿نَارُ اللّٰهِ الْمُوْقَدَةُ الَّتِيْ تَطَّلِعُ عَلَي الْاَفْـِٕدَةِ﴾ (Al-Humazah 104:6–7)