A verb for “wash” in the Qenya Lexicon of the 1910s with variants allu, alnu-, both under the early root ᴱ√ALU “cleanse, dress” (QL/30).
Early Quenya
sovo-
verb. to wash
allu-
verb. to wash
alnu-
verb. to wash
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A verb appearing as ᴱQ. sovo- “wash” in the Qenya Lexicon of the 1910s derived from the early root ᴱ√SOVO or ᴱ√SOW̯O “wash” (QL/86).
Neo-Quenya: In some Neo-Quenya writings (including earlier versions of this lexicon), ᴺQ. sov- is used as the neologism for “wash”. However, in 2024 the word Q. hwal- “wash” was published in PE23, and this is now preferable to sov- for this meaning. I am currently retaining sov- as a neologism for “✱bathe” instead, but may revisit this in future versions of this lexicon.