concern vs languor

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. 

languor

noun
  • Melancholy caused by lovesickness, sadness, etc.; (countable) an instance of this. 

  • A state of the body or mind caused by exhaustion or disease and characterized by a languid or weary feeling; lassitude; (countable) an instance of this. 

  • Dullness, sluggishness; lack of vigour; stagnation. 

  • Listless indolence or inactivity, especially if enjoyable or relaxing; dreaminess; (countable) an instance of this. 

  • Heavy humidity and stillness of the air. 

verb
  • To languish. 

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