Definition "chapter" in Collins English Dictionary & Thesaurus

chapter (chapters plural )

1 n-count A chapter is one of the parts that a book is divided into. Each chapter has a number, and sometimes a title.
also N num
Chromium supplements were used successfully in the treatment of diabetes (see Chapter 4)..., I took the title of this chapter from one of my favorite books.

2 n-count A chapter in someone's life or in history is a period of time during which a major event or series of related events takes place.
WRITTEN supp N, oft N in n, adj N
This had been a particularly difficult chapter in Lebanon's recent history., ...one of the most dramatic chapters of recent British politics.

chapter house (chapter houses plural )

1 n-count A chapter house is the building or set of rooms in the grounds of a cathedral where the members of the clergy hold their meetings.

2 n-count In a university or college, a chapter house is the place where a fraternity or sorority lives or meets.
(AM)

social chapter
The social chapter is an agreement between countries in the European Union concerning workers' rights and working conditions. n-sing the N