Chapther

This word has the same definition as the word "Chapter". It's just a fancier way of saying it.

Here is the definition of Chapter:

chap·ter
/ˈCHaptər/

noun
1.
a main division of a book, typically with a number or title.

Similar:
section
division
part
portion
segment
component
bit
installment
2.
a period of time or an episode in a person's life, a nation's history, etc.
"a tragic chapter in European history"