A rejected noun for “grave” in a deleted entry in The Etymologies written around 1937 for the root ᴹ√DAG “dig” (EtyAC/DAG).
Conceptual Development: There was a word ᴱQ. kaune “grave” in the Qenya Lexicon and Poetic and Mythological Words of Eldarissa of the 1910s based on the early root ᴱ√KAVA which also meant “dig” (QL/45; PME/45). In the first version of the ᴱQ. Oilima Markirya poem and its drafts written around 1930, Tolkien used ᴱQ. sapsa or sapta for “grave” (MC/221; PE16/75), a word that is clearly based on another root meaning “dig”: ᴱ√SAPA.
Neo-Quenya: Since √SAP appeared in Tolkien’s later writings with the same or similar meaning (PE19/86), I’d adapted ᴺQ. sapta for “grave”, along with the meaning “(delved) hole, pit”; see that entry for discussion.