Where does “burius” come from?

burius (Latin) comes from Latin furvus, from Proto-Indo-European dʰwēs- — to breathe.

Ancestry of “burius”, step by step

Step	Language	Word	Meaning
1	Latin	furvus	dark, dusky, gloomy, swarthy, black
2	Proto-Indo-European	dʰwēs-	to breathe