An Etymological Dictionary of the German Language/Annotated/düster

by Friedrich Kluge

düster, adjective (unknown to Upper German?), ‘gloomy, dismal, sad,’ from the equivalent Low German düster, dûster; compare Old Saxon thiustri, Anglo-Saxon þeóstre, þŷstre, ‘dark,’ Middle High German dinster, Old High German dinstar, Old High German finstar, Old Saxon finistar are remarkable parallel forms expressing the same idea; so too Anglo-Saxon þeóstru, ‘darkness.’ The primary form may be seen in the stem of dämmern, Gothic *þimis, ‘twilight,’ Old Indian támas, ‘darkness’; Latin tenebrae (for *temebrae) comes nearest perhaps to Middle High German dinster. f is interchanged with þ in Fackel, Anglo-Saxon þœcele; in the same way finster might be related to dinstar (from þinstar). These guesses are, however, too uncertain.