وَوُجُوهٌ يَوْمَئِذٍۭ بَاسِرَةٌ
Wa wujoohuny yawma 'izim baasirah
and on that Day there will be the sad and despairing faces
and on that day other faces will be darkened,
Bāsira has a single occurrence, this one, while the verb behind it belongs to the surah immediately before, where a man frowns and scowls as he makes up his mind against the recitation. The same expression is put on a face here, on the day that decision is answered. The word names the tightening itself and leaves the reason to the line that follows.