Where does “solar” come from?

solar (Bikol Central) comes from Spanish solar, from Spanish suelo, from Old Spanish suelo, from Latin sōlum, from Proto-Indo-European swol- — sole; sole of the foot.

Ancestry of “solar”, step by step

Step	Language	Word	Meaning
1	Spanish	solar	ground, land
2	Spanish	suelo	ground, floor; soil; “I usually”
3	Old Spanish	suelo	ground
4	Latin	sōlum	bottom, ground, base, foundation, bed
5	Proto-Indo-European	swol-	sole; sole of the foot

Every word from Proto-Indo-European swol- →Every word from Latin sōlum →Every word from Old Spanish suelo →