concert vs obstruct

concert

verb
  • To act in harmony or conjunction; to form combined plans. 

  • To plan; to devise; to arrange. 

  • To plan together; to settle or adjust by conference, agreement, or consultation. 

noun
  • A musical entertainment in which several voices or instruments take part. 

  • Agreement in a design or plan; union formed by mutual communication of opinions and views; accordance in a scheme; harmony; simultaneous action. 

  • Musical accordance or harmony; concord. 

obstruct

verb
  • To get in the way of so as to hide from sight. 

  • To impede, retard, or interfere with; hinder. 

  • To block or fill (a passage) with obstacles or an obstacle. See synonyms at block. 

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