concern vs demon

concern

noun
  • A worry; a sense that something may be wrong; an identification of a possible problem. 

  • The placement of interest or worry on a subject. 

  • The expression of solicitude, anxiety, or compassion toward a thing or person. 

  • That which affects one’s welfare or happiness. A matter of interest to someone. 

  • A business, firm or enterprise; a company. 

  • Any set of information that affects the code of a computer program. 

verb
  • To engage by feeling or sentiment; to interest. 

  • To relate or belong to; to have reference to or connection with; to affect the interest of; to be of importance to. 

  • To make somebody worried. 

demon

noun
  • A person's fears or anxieties. 

  • A false god or idol; a Satanic divinity. 

  • A person's inner spirit or genius; a guiding or creative impulse. 

  • A spirit not considered to be inherently evil; a (non-Christian) deity or supernatural being. 

  • Someone with great strength, passion or skill for a particular activity, pursuit etc.; an enthusiast. 

  • A very wicked or malevolent person; also (in weakened sense) a mischievous person, especially a child. 

  • A tutelary deity or spirit intermediate between the major Olympian gods and mankind, especially a deified hero or the entity which supposedly guided Socrates, telling him what not to do. 

  • An evil spirit resident in or working for Hell; a devil. 

  • A source (especially personified) of great evil or wickedness; a destructive feeling or character flaw. 

  • A hypothetical entity with special abilities postulated for the sake of a thought experiment in philosophy or physics. 

  • Any of various hesperiid butterflies of the genera Notocrypta and Udaspes. 

  • A type of patience or solitaire (card game) played in the UK and/or US. 

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