黑心

hēixīn
  1. ruthless and lacking in conscience
  2. vicious mind full of hatred and jealousy
  3. black core (flaw in pottery)

CEDICT

Entry Composition

1 黑 hēi
  1. black
  2. dark
  3. sinister
  4. secret
  5. shady
  6. illegal
  7. to hide (sth) away
  8. to vilify
  9. (loanword) to hack (computing)
2 心 xīn
  1. heart
  2. mind
  3. intention
  4. center
  5. core

classifiers: 顆, 個