Some researchers consider this term a simple borrowing from German dumm (“stupid”). Others derive it (and its parallel o-stem dialectal variant dums) from Proto-Baltic *dum-, *dūm-, from Proto-Indo-European *dʰu-, *dʰū- (“to be dusty; to whirl; to blow”), whence also dūmi (“smoke”) (q.v.). The original meaning, possibly influenced by dūmi, was apparently “gray, dark brown” (compare Sudovian dumo (“dark”)). There apparently is a relation between dark colors and the human spirit or mind (compare Sanskrit धूमः (dhūmáḥ, “smoke”), धूम्रः (dhūmráḥ, “gray, smokey color; spiritually dazed, enchanted, obsessed”), or Ancient Greek θυμιάω (thumiáō, “to smoke, to puff smoke”), θυμόομαι (thumóomai, “to get angry”)). At this point, Middle Low German dum (“stupid”) (compare German dumm) probably influenced the semantic development of dumjš. Cognates include Middle Low German dum, Old High German tumb, Gothic 𐌳𐌿𐌼𐌱𐍃 (dumbs).