chapter

(noun) a subdivision of a written work; usually numbered and titled. Example: "He read a chapter every night before falling asleep."

(noun) any distinct period in history or in a person's life. Examples: "The industrial revolution opened a new chapter in british history." "The divorce was an ugly chapter in their relationship."

(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) a series of related events forming an episode. Example: "A chapter of disasters."