蝦夷方言藻汐草

Kayano and NINJAL directly give settompa for a grave or cemetery, matching 墓所. Batchelor’s Setomba has the same sense and suggests a Buddhist/Japanese origin; the Mukawa gloss also compares 卒塔婆. Those are reported etymological comparisons, not a demonstrated borrowing history. The source’s ツ supports the doubled t in the retained form. Setompa compares the shorter spelling; tusir is an independently attested different grave word. The three corpus records concern a grave, the borrowing comparison and the NINJAL entry; they are not three early field attestations.