Dictionary.com
Thesaurus.com
Synonyms

treatise

American  
[tree-tis] / ˈtri tɪs /

noun

  1. a formal and systematic exposition in writing of the principles of a subject, generally longer and more detailed than an essay.

treatise British  
/ ˈtriːtɪz /

noun

  1. a formal work on a subject, esp one that deals systematically with its principles and conclusions

  2. an obsolete word for narrative

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of treatise

1300–50; Middle English tretis < Anglo-French tretiz, akin to Old French traitier to treat

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Reading Mr. Emanuel’s treatise reminded me of a conference we had with our son’s fourth-grade teacher in the early 1970s.

From The Wall Street Journal • Jan. 26, 2026

Too much time spent on Marty’s mother or his fierce opponent would distract from the film’s momentum, reducing it to simply a sports movie, and not a conclusive treatise on the cruelty of desire.

From Salon • Dec. 25, 2025

Johann Fischer's 1852 treatise on lizard neuroanatomy included part of the coil but omitted the remainder, and Fischer never described the curled structure.

From Science Daily • Nov. 19, 2025

Evans told reporters he would not describe the notebook found in the car as a "manifesto" as it was not "a treatise on all kinds of ideology and writings".

From BBC • Jun. 16, 2025

Some schoolmates and I were in Ezra Malik’s garden studying a Talmudic treatise.

From "Night" by Elie Wiesel

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.