iron maiden

from WordNet (r) 3.0 (2006)

iron maiden
    n 1: instrument of torture consisting of a hollow iron frame
         shaped like the human body and lined with spikes to impale
         the victim

from The Collaborative International Dictionary of English v.0.48

iron maiden \i"ron maid"en\, n.
   An instrument of torture used in the middle ages, consisting
   of a box large enough to hold a person, often in the shape of
   a woman, and having multiple sharp spikes on the inside.
   Called also the {iron maiden of Nuremberg}.
   [PJC]