शोभनः प्रसादो यस्य अपकारवतामपि शिशुपालादीनां मोक्षप्रदातृत्वादिति सुप्रसादः ।रजस्तमोभ्यामकलुषित आत्मा अन्तःकरणमस्येति प्रसन्नात्मा; यद्वा, प्रसन्नस्वभावः
In plain words
His grace is a beautiful thing: he handed liberation even to the men who worked against him — Śiśupāla and others like him. Hence Suprasāda, whose favour is good. And his ātman — his inner instrument, mind and intellect and sense of self — takes no stain from rajas or tamas. Hence Prasannātmā, whose self is clear. Or read the name more simply: serenity is his nature.
Close to the Sanskrit
He whose grace is beautiful, because of his being the bestower of liberation even upon those who did him harm, Śiśupāla and the rest — thus, Suprasāda. His ātman, that is, his inner instrument, is unmuddied by rajas and tamas — thus, Prasannātmā; or else, one whose very nature is serene.