Nibbana -- A "dhamma", a "dhatu" -- or utter extinguishment?

So how do you explain the word " yadidaṁ"? The whole list madanimmadano pipāsavinayo ālayasamugghāto vaṭṭupacchedo taṇhākkhayo virāgo nirodho nibbānaṁ go together to explain the fading away at the beginning.