דוך
־ן
דער
'breath'

ETYMOLOGY

Polish duch, Ukrainian дух, Belarusian дух; also Russian дух, Old Church Slavonic duxŭ 'breath, spirit' < Proto-Slavic ✱dȗxъ 'breath, spirit' < Proto-Balto-Slavic ✱douṣos; cf. Lithuanian daũsos 'air, breath', dùsti 'to suffocate', dùsas 'asthma'.
Related: Polish dusza 'soul, spirit' (see דושעניו), Russian душа́, Old Church Slavonic duša < Proto-Slavic dušà 'soul' < Proto-Balto-Slavic ✱douṣjaʔ; from PIE dʰous-i-eh₂; Lithuanian daũsios 'air'.
English to doze, MHG dosen 'to keep oneself awake, slumber'; from PGmc ✱dusēn- 'to slumber (originally perhaps: to lose one's sense)'. "Apparently the Indo-Europeans assumed that the spirit (i.e. 'breath') left the body during sleep" (Kroonen).
Latin furō 'to be mad, rave', OE dēor, English deer, OHG tior 'wild animal', NHG Tier (see 2 טיר); from PGmc ✱deuza- '(wild) animal < ✱dʰeus-ó- (EUR), from the root ✱dʰu̯es- 'to breathe'.