Where does “burius” come from?

burius (Vulgar Latin) comes from Latin Burrus, from Ancient Greek πυρρός, from Ancient Greek πῦρ, from Proto-Indo-European péh₂wr̥ — bonfire; spelt.

Ancestry of “burius”, step by step

Step	Language	Word	Meaning
1	Latin	Burrus	flushed, red
2	Ancient Greek	πυρρός	flame-coloured, yellowish-red; red-haired,...
3	Ancient Greek	πῦρ	a fire; lightning; a fever
4	Proto-Indo-European	péh₂wr̥	bonfire; spelt