अतिदारुणे very dreadful, अस्मिन् वैरे his enmity, सुग्रीवः Sugriva, अद्य now, कृतकृत्यः has achieved his goal, यस्य at whose, भयम् fear, रामविमुक्तेन released by Rama, एकेषुणा one single arrow, हृतम् is dispelled.

'Sugriva has achieved his goal in his dreadful enmity (with you). His fear is dispelled by a single arrow released by Rama.