:to decline from a sound or prosperous condition
:to decrease usually gradually in size, quantity, activity, or force
- The three voices … decayed and died out upon her ear.
- —Thomas Hardy
:to fall into ruin
- the city's decaying neighborhoods
:to decline in health, strength, or vigor
- Her mind is beginning to decay with age.
- believes that the moral fiber of our society is decaying
:to undergo decomposition
- … most isotopes of copper decay quickly, but two are stable: Cu-63 and Cu-65.
- —David E. Thomas
:to cause to decay :impair
- infirmity that decays the wise
- —William Shakespeare
:to destroy by decomposition