• كِسَف
• كِسْف

Appears 5 times in the Quran.

1. 17:92 أَوْ تُسْقِطَ ٱلسَّمَآءَ كَمَا زَعَمْتَ عَلَيْنَا كِسَفًا أَوْ تَأْتِىَ بِٱللَّهِ وَٱلْمَلَٰٓئِكَةِ قَبِيلًا

   Or you should cause the heaven to come down upon us in pieces as you think, or bring Allah and the angels face to face (with us).
   

2. 26:187 فَأَسْقِطْ عَلَيْنَا كِسَفًا مِّنَ ٱلسَّمَآءِ إِن كُنتَ مِنَ ٱلصَّٰدِقِينَ

   Therefore cause a portion of the heaven to come down upon us, if you are one of the truthful.
   

3. 30:48 ٱللَّهُ ٱلَّذِى يُرْسِلُ ٱلرِّيَٰحَ فَتُثِيرُ سَحَابًا فَيَبْسُطُهُۥ فِى ٱلسَّمَآءِ كَيْفَ يَشَآءُ وَيَجْعَلُهُۥ كِسَفًا فَتَرَى ٱلْوَدْقَ يَخْرُجُ مِنْ خِلَٰلِهِۦ فَإِذَآ أَصَابَ بِهِۦ مَن يَشَآءُ مِنْ عِبَادِهِۦٓ إِذَا هُمْ يَسْتَبْشِرُونَ

   Allah is he Who sends forth the winds so they raise a cloud, then He spreads it forth in the sky as He pleases, and He breaks it up so that you see the rain coming forth from inside it; then when He causes it to fall upon whom He pleases of His servants, lo! they are joyful
   

4. 34:9 أَفَلَمْ يَرَوْا۟ إِلَىٰ مَا بَيْنَ أَيْدِيهِمْ وَمَا خَلْفَهُم مِّنَ ٱلسَّمَآءِ وَٱلْأَرْضِ إِن نَّشَأْ نَخْسِفْ بِهِمُ ٱلْأَرْضَ أَوْ نُسْقِطْ عَلَيْهِمْ كِسَفًا مِّنَ ٱلسَّمَآءِ إِنَّ فِى ذَٰلِكَ لَءَايَةً لِّكُلِّ عَبْدٍ مُّنِيبٍ

   Do they not then consider what is before them and what is behind them of the heaven and the earth? If We please We will make them disappear in the land or bring down upon them a portion from the heaven; most surely there is a sign in this for every servant turning (to Allah).
   

5. 52:44 وَإِن يَرَوْا۟ كِسْفًا مِّنَ ٱلسَّمَآءِ سَاقِطًا يَقُولُوا۟ سَحَابٌ مَّرْكُومٌ

   And if they should see a portion of the heaven coming down, they would say: Piled up clouds.