A noun appearing as ᴱQ. sausa in the Qenya Lexicon of the 1910s glossed “bath water, hot water” derived from the early root ᴱ√SOVO or ᴱ√SOW̯O “wash” (QL/86). Very likely the ancient ou became au as was the usual phonetic development in Qenya of the 1910s and 20s.

Neo-Quenya: I retain ᴺ√SOW “wash” for purposes of Neo-Quenya, so I would adapt this word as ᴺQ. súsa “bath water, hot water” using the later sound change of ou to ū. To explain the intervocalic s, I assume the archaic form of this noun was southā; compare G. soth “bath”.