decline vs degradation

decline

noun
  • A reduction or diminution of activity. 

  • A weakening. 

  • Downward movement, fall. 

  • The act of declining or refusing something. 

  • A sloping downward, e.g. of a hill or road. 

verb
  • To choose not to do something; refuse, forbear, refrain. 

  • To run through from first to last; to recite in order as though declining a noun. 

  • To cause to decrease or diminish. 

  • To bend downward; to bring down; to depress; to cause to bend, or fall. 

  • To turn or bend aside; to deviate; to stray; to withdraw. 

  • To move downwards, to fall, to drop. 

  • To inflect for case, number, gender, and the like. 

  • To reject a penalty against the opposing team, usually because the result of accepting it would benefit the non-penalized team less than the preceding play. 

  • To become weaker or worse. 

  • To recite all the different declined forms of (a word). 

degradation

noun
  • Diminution or reduction of strength, efficacy, or value; degeneration; deterioration. 

  • The state of being reduced in rank, character, or reputation; baseness; moral, physical, or intellectual degeneracy; disgrace; abasement; debasement. 

  • The act of reducing in rank, character, or reputation, or of abasing; a lowering from one's standing or rank in office or society 

  • A deleterious change in the chemical structure, physical properties or appearance of a material from natural or artificial exposure. 

  • The state or condition of a species or group which exhibits degraded forms; degeneration. 

  • Arrest of development, or degeneration of any organ, or of the body as a whole. 

  • The gradual breakdown of components of a material, as a result of a natural element, i.e.: heat, cold and wind. 

  • A gradual wearing down or wasting, as of rocks and banks, by the action of water, frost etc. 

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