Subentries are smaller parts of a bigger entry in a list or a book.
Subentries help organize information and make it easier to find what you need.
Examples:
In the dictionary, the word 'run' has many subentries.
The subentries in the table of contents help you find the right page.
I found the recipe in the subentries under 'desserts'.
The subentries for 'animals' in the encyclopedia are very interesting.
The subentries for 'space' in the book are out of this world!
I like to read the subentries about dinosaurs in the book.