From Proto-Balto-Slavic *drugjas (“trembling”); Baltic cognates include Latvian drudzis (“fever, ague”), Lithuanian drugỹs (“fever, malaria; butterfly, moth”). Further relations outside of Balto-Slavic unclear; the mechanical reconstruction of a further Proto-Indo-European *drugʰ- or *dʰrugʰ- (“to shake off, drain”) yields phonetic matches with terms including Proto-Germanic *draugiz, *drūgiz (“dry”), and Proto-Indo-European *dʰrewgʰ- (“to deceive; to accompany”), none of which are semantically convincing. Only the Germanic terms meaning "dry" could reasonably be linked, though the semantic shifts required would still be non-trivial.
singular | dual | plural | |
---|---|---|---|
nominative | *drъžь | *drъži | *drъžьje, *drъže* |
genitive | *drъži | *drъžьju, *drъžu* | *drъžьjь, *drъži* |
dative | *drъži | *drъžьma | *drъžьmъ |
accusative | *drъžь | *drъži | *drъži |
instrumental | *drъžьmь | *drъžьma | *drъžьmi |
locative | *drъži | *drъžьju, *drъžu* | *drъžьxъ |
vocative | *drъži | *drъži | *drъžьje, *drъže* |
* The second form occurs in languages that contract early across /j/ (e.g. Czech), while the first form occurs in languages that do not (e.g. Russian).