• نُحَاس
• نَحْس
• نَّحِسَات

Appears 3 times in the Quran.

1. 41:16 فَأَرْسَلْنَا عَلَيْهِمْ رِيحًا صَرْصَرًا فِىٓ أَيَّامٍ نَّحِسَاتٍ لِّنُذِيقَهُمْ عَذَابَ ٱلْخِزْىِ فِى ٱلْحَيَوٰةِ ٱلدُّنْيَا وَلَعَذَابُ ٱلْءَاخِرَةِ أَخْزَىٰ وَهُمْ لَا يُنصَرُونَ

   So We sent on them a furious wind in unlucky days, that We may make them taste the chastisement of abasement in this world's life; and certainly the chastisement of the hereafter is much more abasing, and they shall not be helped.
   

2. 54:19 إِنَّآ أَرْسَلْنَا عَلَيْهِمْ رِيحًا صَرْصَرًا فِى يَوْمِ نَحْسٍ مُّسْتَمِرٍّ

   Surely We sent on them a tornado in a day of bitter ill-luck
   

3. 55:35 يُرْسَلُ عَلَيْكُمَا شُوَاظٌ مِّن نَّارٍ وَنُحَاسٌ فَلَا تَنتَصِرَانِ

   The flames of fire and smoke will be sent on you two, then you will not be able to defend yourselves.