wateryoudaoicibaDictYouDict[water 词源字典]
water: [OE] Water is an ancient and widespread word, which goes back ultimately to prehistoric Indo-European *wodōr. Its relatives include Greek húdōr ‘water’ (source of the English prefix hydro-), Latin unda ‘wave’ (source of English redundant, surround, undulate, etc), Russian voda ‘water’ (source of English vodka), Gaelic uisge ‘water’ (source of English whisky), Lithuanian vanduō ‘water’, Latvian ūdens ‘water’, Sanskrit udán ‘water’, and Hittite watar ‘water’.

In the Germanic languages it has become German wasser (source of English vaseline), Dutch and English water, Swedish vatten, and Danish vand. Otter comes from a variant of the same Indo-European base, as may winter, and wet is closely related.
=> abound, hydro-, otter, redundant, surround, undulate, vaseline, vodka, wet, whisky[water etymology, water origin, 英语词源]
water (n.1)youdaoicibaDictYouDict
Old English wæter, from Proto-Germanic *watar (cognates: Old Saxon watar, Old Frisian wetir, Dutch water, Old High German wazzar, German Wasser, Old Norse vatn, Gothic wato "water"), from PIE *wod-or, from root *wed- (1) "water, wet" (cognates: Hittite watar, Sanskrit udrah, Greek hydor, Old Church Slavonic and Russian voda, Lithuanian vanduo, Old Prussian wundan, Gaelic uisge "water;" Latin unda "wave").

To keep (one's) head above water in the figurative sense is recorded from 1742. Water cooler is recorded from 1846; water polo from 1884; water torture from 1928. Linguists believe PIE had two root words for water: *ap- and *wed-. The first (preserved in Sanskrit apah as well as Punjab and julep) was "animate," referring to water as a living force; the latter referred to it as an inanimate substance. The same probably was true of fire (n.).
water (v.)youdaoicibaDictYouDict
Old English wæterian "moisten, irrigate, supply water to; lead (cattle) to water;" from water (n.1). Meaning "to dilute" is attested from late 14c.; now usually as water down (1850). To make water "urinate" is recorded from early 15c. Related: Watered; watering.
water (n.2)youdaoicibaDictYouDict
measure of quality of a diamond, c. 1600, from water (n.1), perhaps as a translation of Arabic ma' "water," which also is used in the sense "lustre, splendor."