The Collaborative International Dictionary of English v.0.48:

rotenone \ro"te*none\, n.
   A chemical substance (C23H22O6) extracted from the root of
   the derris (Derris elliptica, Derris malaccensis, and
   other species), used in treatment of scabies and as an
   insecticide for external infestation by chiggers in human
   medicine, and in veterinary medicine for the treatment of
   infestations with fleas, ticks, and lice.
   [PJC]

WordNet (r) 3.0 (2006):

rotenone
    n 1: a white crystalline insecticide that has low toxicity for
         mammals; is used in home gardens; extracted from the roots
         of derris and cube