To rubricate means to add red letters or decoration to a book or manuscript.
Rubricating is an old way of making books look special and important.
Examples:
The monks rubricate the old book.
She learned how to rubricate the letters.
Rubricating is a way to make books look pretty.
I want to rubricate my diary with sparkles!
In the olden days, only important books were rubricated.
He rubricates the book with care and patience.