Where does “souillure” come from?

souillure (French) comes from French souiller, from Middle French souiller, from Old French soillier, from Frankish *sulwijan, from Proto-Germanic sulwijaną, from Proto-Indo-European sūl- — thick liquid, muck.

souillure (French): stain, taint, blemish

Definitions

stain, taint, blemish

Ancestry of “souillure”, step by step

Step	Language	Word	Meaning
1	French	souiller	to soil, sully, dirty; to make unclean or impure;...
2	Middle French	souiller	—
3	Old French	soillier	Alternative form of souillier; to soil
4	Frankish	*sulwijan	—
5	Proto-Germanic	sulwijaną	to make dirty; to sully
6	Proto-Indo-European	sūl-	thick liquid, muck

Every word from Proto-Indo-European sūl- →Every word from Proto-Germanic sulwijaną →Every word from Frankish *sulwijan →