A noun appearing as G. sard “table” in the Gnomish Lexicon of the 1910s, which Tolkien compared to G. thrad “plank” (GL/67, 73). It was likely based on the early root ᴱ√SARA from the contemporaneous Qenya Lexicon having to do with sawing and sawed things like planks (QL/82). However, elsewhere in Gnomish Lexicon Tolkien had G. thar- “ to saw (up)” indicating a variant or revised root ᴱ√ÞARA (GL/72).

Neo-Sindarin: For purposes of Neo-Sindarin, I would assume the verbal sense of thar- “to saw” might still be viable as related to the later root √THAR¹ “*across” (referring to a sawing motion). From this I would adapt the Gnomish word for “table” as ᴺS. sardh, where the final rd became rdh as with words like gardh, and the initial s is due to dissimilation of th away from the final spirant dh; compare to úsaeth a deleted variant of úthaes (VT44/30).