Tome

WORD OF THE DAY

tome / noun / TOHM 
 
Definition
1: a volume forming part of a larger work
2: book; especially : a large or scholarly book

Examples
It took me more than a month to finish reading that 800-page tome on the French Revolution.

"I also bring a book I've never read, some large tome that I'm wary of, but that I also think will captivate me once I'm on page one hundred, and I won't be able to put it down."
— Alejandro Zambra, Not To Read (translated by Megan McDowell), 2018

Did You Know?
Tome comes from Latin tomus, which comes from Greek tomos, meaning "section" or "roll of papyrus." Tomos is from the Greek verb temnein, which means "to cut." 

In ancient times, some of the longest scrolls of papyrus occasionally were divided into sections. When it was first used in English in the 16th century, tome was a book that was a part of a multi-volume work or a major part of a single-volume book. 

Now a tome is most often simply a large and often ponderous book.