n. & v.
n. 1 a part that an animal casts or moults, esp. a snake's cast skin. 2 dead tissue that drops off from living flesh etc. 3 a habit etc. that has been abandoned.
v. 1 tr. cast off as a slough. 2 intr. (often foll. by off) drop off as a slough. 3 intr. cast off a slough. 4 intr. (often foll. by away, down) (of soil, rock, etc.) collapse or slide into a hole or depression. sloughy adj.
[ ME, perh. rel. to LG slu(we) husk ]