tome

tome \tohm\, noun:

a large, often scholarly, book

An unabridged dictionary is a tome.

by 1519, from Middle French tome, from Latin tomus "section of a book, tome," from Greek tomos "volume, section of a book," originally "section, piece cut off," from temein "to cut," from Proto Indo-European *tom-/*tem- "to cut." Originally "a single volume of a multi-volume work;" sense of "a large book" is attested from 1573.