decay
1 : to lose soundness, health, strength, or vigor
2 : to go through or cause to go through decomposition decays> decayed in storage>
2 : to go through or cause to go through decomposition decays> decayed in storage>
http://www.wordcentral.com/cgi-bin/student?book=Student&va=decay
I found a decayed apple in my desk from three months ago, it was tiny and had turned brown.