heart-spoon

from The Collaborative International Dictionary of English v.0.48

Heart-spoon \Heart"-spoon`\ (h[aum]rt"sp[=oo]n`), n.
   A part of the breastbone. [Obs.]
   [1913 Webster]

         He feeleth through the herte-spon the pricke.
                                                  --Chaucer.
   [1913 Webster]