Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

setterwort
     n : digitate-leaved hellebore with an offensive odor and
         irritant qualities when taken internally [syn: {stinking
         hellebore}, {bear's foot}, {Helleborus foetidus}]