变质

變質
biànzhì
  1. to degenerate; to deteriorate
  2. (of food) to go bad; to go off
  3. (geology) metamorphism

CEDICT

geology

Entry Composition

1 变 biàn
  1. to change
  2. to become different
  3. to transform
  4. to vary
  5. rebellion
2 质 zhì
  1. character
  2. nature
  3. quality
  4. plain
  5. to pawn
  6. pledge
  7. hostage
  8. to question
  9. Taiwan pr. zhí