decay vs rot

decay

verb
  • To deteriorate, to get worse, to lose strength or health, to decline in quality. 

  • To undergo bit rot, that is, gradual degradation. 

  • To undergo optical decay, that is, to relax to a less excited state, usually by emitting a photon or phonon. 

  • Loss of airspeed due to drag. 

  • To undergo software rot, that is, to fail to be updated in a changing environment, so as to eventually become legacy or obsolete. 

  • To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons; to undergo radioactive decay. 

  • To cause to rot or deteriorate. 

  • Of an array: to lose its type and dimensions and be reduced to a pointer, for example when passed to a function. 

  • To rot, to go bad. 

  • To undergo prolonged reduction in altitude (above the orbited body). 

noun
  • The process or result of being gradually decomposed. 

  • A deterioration of condition; loss of status or fortune. 

  • The situation, in programming languages such as C, where an array loses its type and dimensions and is reduced to a pointer, for example by passing it to a function. 

rot

verb
  • To (cause to) deteriorate in any way, as in morals; to corrupt. 

  • To expose, as flax, to a process of maceration, etc., for the purpose of separating the fiber; to ret. 

  • To spend a long period of time (in an unpleasant place). 

  • To suffer decomposition due to biological action, especially by fungi or bacteria. 

  • To decline in function or utility. 

  • To make putrid; to cause to be wholly or partially decomposed by natural processes. 

noun
  • Any of several diseases in which breakdown of tissue occurs. 

  • The process of becoming rotten; putrefaction. 

  • Verbal nonsense. 

  • Decaying matter. 

How often have the words decay and rot occurred in a corpus of books? (source: Google Ngram Viewer )