n.
    - a main division of a book. 
▸an Act of Parliament numbered as part of a session's proceedings.
 - a distinctive period in history or in a person's life.
 - the governing body of a cathedral or other religious community, or of a knightly order.
 - chiefly N. Amer. a local branch of a society.
 
 
  Phrase
  
    - chapter and verse
 an exact reference or authority.  - a chapter of accidents
 a series of unfortunate events. 
   
  Etymology
  ME: from OFr. chapitre, from L. capitulum, dimin. of caput ‘head’.