Where does “preswylwr” come from?

preswylwr (Welsh) comes from Welsh preswylio, from Welsh preswyl, from Old Welsh pressuir.

Ancestry of “preswylwr”, step by step

StepLanguageWordMeaning
1Welshpreswylioto dwell, to reside
2Welshpreswylresidential, live-in
3Old Welshpressuir—
Every word from Old Welsh pressuir →Every word from Welsh preswyl →Every word from Welsh preswylio →