1) To singe, scorch or burn, a regional word of Old Norse origin although the vocabulary references are quite late.
1681 the grasse upon the the hay-ground went back so that many fell to mowing to take what there was, lest all should be swithend away, Northowram. Minor place-names provide much earlier evidence: 1246 Swythengate
1404 ‘one piece of land called Swythenknoll’, Old Lindley
1472 ‘an acre of land in Swythenhyll’, Barnsley. See Swithenbank.