Where does “Ambròs” come from?

Ambròs (Lombard) comes from Latin ambrosius, from Ancient Greek ἀμβρόσιος, from Ancient Greek ἄμβροτος, from Proto-Indo-European n̥mr̥tós, from Proto-Indo-European n̥-, from Proto-Indo-European ne — not.

Ancestry of “Ambròs”, step by step

Step	Language	Word	Meaning
1	Latin	ambrosius	Ambrosial, divine, immortal
2	Ancient Greek	ἀμβρόσιος	immortal, divine
3	Ancient Greek	ἄμβροτος	immortal, divine; belonging to the gods
4	Proto-Indo-European	n̥mr̥tós	immortal
5	Proto-Indo-European	n̥-	not, un-
6	Proto-Indo-European	ne	not

Every word from Proto-Indo-European ne →Every word from Proto-Indo-European n̥- →Every word from Proto-Indo-European n̥mr̥tós →