। ॥ ४३९ ॥
In plain words
He is called Vaiśvānara because he takes himself to be the Self in every being — not living among them but being them. He is called Virāṭ because he himself, and nothing else, shines out as all this variety.
Close to the Sanskrit
Vaiśvānara, from identification as the Self in all men; Virāṭ he would be, from shining forth himself alone in manifold form.