Where does “sotão” come from?

sotão (Old Portuguese) comes from Vulgar Latin subtulum, from Latin subtus, from Latin sub, from Proto-Italic supo, from Proto-Indo-European upó, from Proto-Indo-European h₃ewp-.

Ancestry of “sotão”, step by step

StepLanguageWordMeaning
1Vulgar Latinsubtulum—
2Latinsubtusbelow, underneath, beneath
3Latinsubunder, beneath; behind; at the feet of
4Proto-Italicsupounder
5Proto-Indo-Europeanupóunder, below
6Proto-Indo-Europeanh₃ewp-—
Every word from Proto-Indo-European h₃ewp- →Every word from Proto-Indo-European upó →Every word from Proto-Italic supo →