Etymology

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).^[1]

Pronunciation