An adjective appearing as ᴱQ. satwa “hollow, dug-out, excavated” in the Qenya Lexicon of the 1910s under the early root ᴱ√SAPA “dig, excavate” (QL/82). It is likely the result of the Early Qenya sound change whereby [pw] became [tw] (PE12/23).

Neo-Quenya: In the rare cases where ancient pw occurred Quenya of the 1930s and later, it became pp (PE19/43, 86). Thus I would update this Early Qenya adjective to ᴺQ. sappa “hollow, dug-out, excavated”.