Nadir is a Diablo 2 Resurrected runeword created by combining nef + tir into a 2 socket helm. It requires at least level 13 to equip.
Nadir is the lowest level runeword in the game. It has no particularly good stats, other than the Cloak of Shadows charges. Because the runes it requires are so easy to find, it's a good first helm option, if you haven't found anything decent by level 13.
Did you know? It takes on average 6 countess runs on Normal difficulty to get this runeword.