blackheart

noun4

1. •
   A cruel and remorseless person.

   • That blackheart would have thrust you out to wail and gained the time himself, without you there. — 2007
2. •
   A type of malleable cast iron with minimum tensile strength of 350 N/mm².

   • Blackheart malleable cast iron has excellent castability and machinability. — 2013
3. •
   Any of various plant diseases that cause darkening of the central tissue.

   • Blackheart results from inadequate oxygen supply for respiration (asphyxiation) of internal tuber tissue. — 1981
4. •
   A heart-shaped cherry with a very dark skin.