decayed; decaying; decays
1
: to undergo decomposition
decaying fruit
Her teeth were decaying.
… most isotopes of copper decay quickly, but two are stable: Cu-63 and Cu-65.—David E. Thomas
2
: to decline in health, strength, or vigor
memories decaying
believes that the moral fiber of our society is decaying
… sources … say the relationship decayed since their friendship began five years ago.—Marcus Hayes
3
: to fall into ruin
the country's decaying castles
4
: to decline from a sound or prosperous condition
a decaying empire
5
: to decrease usually gradually in size, quantity, activity, or force
The three voices … decayed and died out upon her ear.—Thomas Hardy
1
: to destroy by decomposition
wood decayed by bacteria
2
obsolete
: to cause to decay : impair
Infirmity, that decays the wise …—William Shakespeare
decayer
noun
1
2
: gradual decline in strength, soundness, or prosperity or in degree of excellence or perfection
the decay of educational standards
3
: a decline in health or vigor
the patient's physical decay
4
: a wasting or wearing away : ruin
an old theater that had fallen into decay
5
: decrease in quantity, activity, or force: such as
a
chemistry
: spontaneous decrease in the number of radioactive atoms in radioactive material
b
physics
: spontaneous disintegration (as of an atom or a particle)
6
obsolete
: destruction, death
… sullen presage of your own decay.—Shakespeare
Cite this Entry
“Decay.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/decay. Accessed 20 Oct. 2026.
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