“ Regret ” is mental sorrow, pain of mind, at something done or perhaps left undone, and it can mean “to weep again. ”
وَكُلُّ فَرْدٍ مِنَّا لَدَيْهِ مَا يَنْدَمُ عَلَيْهِ وَيَتَمَنَّى لَوْ يَعُودُ بِهِ ٱلزَّمَنُ إِلَى ٱلْوَرَاءِ كَيْ يَتَصَرَّفَ عَلَى نَحْوٍ مُغَايِرٍ .‏