chapter (Noun) — A subdivision of a written work; usually numbered and titled. ex. "he read a chapter every night before falling asleep"
chapter (Noun) — Any distinct period in history or in a person's life. ex. "the industrial revolution opened a new chapter in British history" ex. "the divorce was an ugly chapter in their relationship"
chapter (Noun) — A local branch of some fraternity or association.
chapter (Noun) — An ecclesiastical assembly of the monks in a monastery or even of the canons of a church.
chapter (Noun) — A series of related events forming an episode. ex. "a chapter of disasters"