• ءَافِلِين
• أَفَلَ
• أَفَلَتْ

Appears 3 times in the Quran.

1. 6:76 فَلَمَّا جَنَّ عَلَيْهِ ٱلَّيْلُ رَءَا كَوْكَبًا قَالَ هَٰذَا رَبِّى فَلَمَّآ أَفَلَ قَالَ لَآ أُحِبُّ ٱلْءَافِلِينَ

   So when the night over-shadowed him, he saw a star; said he: Is this my Lord? So when it set, he said: I do not love the setting ones.
   

2. 6:77 فَلَمَّا رَءَا ٱلْقَمَرَ بَازِغًا قَالَ هَٰذَا رَبِّى فَلَمَّآ أَفَلَ قَالَ لَئِن لَّمْ يَهْدِنِى رَبِّى لَأَكُونَنَّ مِنَ ٱلْقَوْمِ ٱلضَّآلِّينَ

   Then when he saw the moon rising, he said: Is this my Lord? So when it set, he said: If my Lord had not guided me I should certainly be of the erring people.
   

3. 6:78 فَلَمَّا رَءَا ٱلشَّمْسَ بَازِغَةً قَالَ هَٰذَا رَبِّى هَٰذَآ أَكْبَرُ فَلَمَّآ أَفَلَتْ قَالَ يَٰقَوْمِ إِنِّى بَرِىٓءٌ مِّمَّا تُشْرِكُونَ

   Then when he saw the sun rising, he said: Is this my Lord? Is this the greatest? So when it set, he said: O my people! surely I am clear of what you set up (with Allah).