Definitions of chapter:

• noun:   a subdivision of a written work; usually numbered and titled

  Example: "He read a chapter every night before falling asleep"

• noun:   a series of related events forming an episode

  Example: "A chapter of disasters"

• noun:   a local branch of some fraternity or association

  Example: "He joined the Atlanta chapter"

• noun:   an ecclesiastical assembly of the monks in a monastery or even of the canons of a church
• noun:   any distinct period in history or in a person's life

  Example: "The industrial revolution opened a new chapter in British history"