Where does “thiūstere” come from?
thiūstere (Old Frisian) comes from Proto-West Germanic þiustrī, from Proto-West Germanic þimstr, from Proto-Germanic þimstraz, from Proto-Indo-European témH-s-ro-s, from Proto-Indo-European temH- — dark.
Ancestry of “thiūstere”, step by step
Words derived from “thiūstere”