/swayl/ , n. Chiefly Northeastern U.S.
1. a low place in a tract of land, usually moister and often having ranker vegetation than the adjacent higher land.
2. a valleylike intersection of two slopes in a piece of land.
[ 1400-50; late ME; orig. a cool, shady spot, perh. svalr cool, or svalir a covered porch ]