Definition of "Chapter" :

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

"He read a chapter every night before falling asleep."

noun: a series of related events forming an episode

"A chapter of disasters."

noun: a local branch of some fraternity or association

"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

"The industrial revolution opened a new chapter in British history."