The Collaborative International Dictionary of English v.0.48:

Setterwort \Set"ter*wort`\, n. (Bot.)
   The bear's-foot (Helleborus f[oe]tidus); -- so called
   because the root was used in settering, or inserting setons
   into the dewlaps of cattle. Called also pegroots. --Dr.
   Prior.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bear's-foot \Bear's"-foot`\ (-f[oo^]t`), n. (Bot.)
   A species of hellebore (Helleborus f[oe]tidus), with
   digitate leaves. It has an offensive smell and acrid taste,
   and is a powerful emetic, cathartic, and anthelmintic.
   [1913 Webster]