complaint vs concern

complaint

noun
  • A grievance, problem, difficulty, or concern. 

  • However, court proceedings, such as a trial, cannot be instituted until an indictment or information has been handed down against the defendant. 

  • In a civil action, the first pleading of the plaintiff setting out the facts on which the claim is based; 

  • The purpose is to give notice to the adversary of the nature and basis of the claim asserted. 

  • The act of complaining. 

  • In criminal law, the preliminary charge or accusation made by one person against another to the appropriate court or officer, usually a magistrate. 

  • A bodily disorder or disease; the symptom of such a disorder. 

concern

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

  • 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. 

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