दन्तान् teeth, विदशतः biting, तस्य his, दशनस्वनः sound from his teeth, दानवैः by Danavas, आवेष्ट्यमाणस्य revolved round, महतः huge, यन्त्रस्येव machine like, श्रूयते heard

When he was biting on his teeth (enraged), the sound from his teeth resembled the sound of a grinder revolved round by Danavas.