a subdivision of a written work; usually numbered and titled; "he read a chapter every night before falling asleep"
a series of related events forming an episode; "a chapter of disasters"
a local branch of some fraternity or association; "he joined the Atlanta chapter"
an ecclesiastical assembly of the monks in a monastery or even of the canons of a church
any distinct period in history or in a person's life; "the industrial revolution opened a new chapter in British history"; "the divorce was an ugly chapter in their relationship"
absolutely required and not to be used up or sacrificed
absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"
being or relating to or containing the essence of a plant etc; "essential oil"