He saw the heads of his classmates meekly bent as they wrote in their notebooks the points they were bidden to note, nominal definitions, essential definitions and examples or dates of birth or death, chief works, a favourable and an unfavourable criticism side by side.
There are no more uses of "essential" in the book.
Show samples from other sources
The essential feature of the pen is that it writes so consistently.
I carry all the essential tools and materials I need in this toolbox.