Where does “residue” come from?

residue (Middle English) comes from Old French residu, from Latin residuum, from Latin residuus, from Latin resideō, from Latin sedeō, from Proto-Italic sedēō, from Proto-Indo-European sḗd- — to sit.

Ancestry of “residue”, step by step

StepLanguageWordMeaning
1Old Frenchresidu
2Latinresiduumnominative neuter singular of residuus;...
3Latinresiduusremaining; residuary; persisting, surviving
4Latinresideōto reside, abide, tarry, linger
5Latinsedeōto sit, to be seated
6Proto-Italicsedēōsit, be sitting, be seated
7Proto-Indo-Europeansḗd-to sit
Every word from Proto-Indo-European sḗd-Every word from Proto-Italic sedēōEvery word from Latin sedeō