dʰewb-
“to dip, to sink into liquid”dip, sink
PIE root meaning to dip or sink into liquid. Ancestral to words for submersion, depth, and dipping.
Discussion
*dʰewb- is a Proto-Indo-European root meaning "to dip" or "to sink into liquid," yielding vocabulary related to submersion, depth, and immersion.
The root gives Old English dēop "deep" (modern English deep) and dȳppan "to dip" (modern English dip), with regular Grimm's Law shifts (*dʰ > d). German tief "deep" and taufen "to baptize" (literally "to dip") show the same development, with the baptismal sense reflecting the early Christian practice of immersion. Dutch diep and dopen follow the same pattern.
The semantic range spans physical depth (deep water), the action of submerging (dip, dip into), and ritual immersion (baptism in Germanic). Lithuanian dubùs "deep" and Old Church Slavonic dŭno "bottom" reflect Balto-Slavic continuations.
The connection between "dipping" and "depth" is semantically transparent—deep water is where one sinks. The ritual extension to baptism in Germanic languages is a notable cultural development, where a PIE root for physical submersion acquired religious significance.
Modern descendants include English deep, dip, dive (possibly), and German taufen "to baptize."
Notes
Source of English "dip", "deep", "dive". Germanic *deupaz (deep).