Appears 3 times in the Quran.
Then they were made to hang down their heads: Certainly you know that they do not speak.
32:12 وَلَوْ تَرَىٰٓ إِذِ ٱلْمُجْرِمُونَ نَاكِسُوا۟ رُءُوسِهِمْ عِندَ رَبِّهِمْ رَبَّنَآ أَبْصَرْنَا وَسَمِعْنَا فَٱرْجِعْنَا نَعْمَلْ صَٰلِحًا إِنَّا مُوقِنُونَ
And could you but see when the guilty shall hang down their heads before their Lord: Our Lord! we have seen and we have heard, therefore send us back, we will do good; surely (now) we are certain.
And whomsoever We cause to live long, We reduce (him) to an abject state in constitution; do they not then understand?